Signal transmission method and device

ABSTRACT

The present invention relates to the field of mobile communications technologies, and in particular, to a signal transmission method and device, so as to reduce a burden on a communications network. A signal transmission method provided in an embodiment of the present invention includes: adjusting, by a first communications node, a sending state of a reference signal of a cell that belongs to the first communications node; and sending, by the first communications node, the reference signal of the cell according to an adjusted sending state of the reference signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/937,356 filed on Nov. 10, 2015, which is a continuation ofInternational Application No. PCT/CN2013/075516 filed on May 10, 2013.All of the afore-mentioned patent applications are hereby incorporatedby reference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of wireless communicationstechnologies, and in particular, to a signal transmission method anddevice.

BACKGROUND

With the development of mobile communications technologies, a user hasincreasingly high demands for a network bandwidth. To enhance efficiencyof transmitting network data, a low power node (LPN, Low Power Node) maybe introduced in a macro cell (macro cell) to form a low power cell, forexample, a micro cell (micro cell), a pico cell (pico cell), or a femtocell (femto cell), to enable these low power cells to cover servicehotspot areas or areas out of cell coverage. In this way, when a userequipment(User Equipment, UE) moves to these areas, a service of the UEmay be handed over to these low power cells, so as to implement serviceoffloading or coverage compensation.

A specific process that UE is handed over to and enters a new cell isgenerally as follows: The UE receives measurement configurationinformation of a communications node (that is, a source communicationsnode) of a source cell in which the UE is located, where the measurementconfiguration information includes measured frequency information.According to the received frequency information, the UE detects areference signal of a target cell corresponding to the frequencyinformation, and measures the target cell whose reference signal isdetected. The UE reports a measurement result to the sourcecommunications node, and after determining, according to the measurementresult, to perform cell handover, the source communications nodeinitiates a handover request to a communications node (that is, a targetcommunications node) of the detected target cell. The targetcommunications node decides, according to a network condition such asload, interference, and a transmission network bandwidth of the targetcell, whether to accept a service of the UE. If the service cannot beaccepted, the target communications node sends information about ahandover rejection or a handover failure to the source communicationsnode, or if the service can be accepted, the target communications nodesends information about a handover agreement or a handoveracknowledgment to the source communications node. FIG. 1 is a schematicdiagram of UE being handed over between different cells in aheterogeneous network.

In the prior art, when a target cell provides a service, a targetcommunications node of the target cell continuously sends a referencesignal. When the target cell turns off the service, a transmitter of thetarget cell is closed, and the target communications node also no longersends the reference signal. Because when the target cell provides theservice, the reference signal of the target cell is sent continuously,even if load of the target cell is very heavy, UE within a coverage areaof the reference signal can also detect the target cell. Aftercompleting measurement of the target cell, the UE reports a measurementresult to a source communications node. After analyzing the measurementresult of the UE and determining to perform cell handover, the sourcecommunications node sends a handover request to the targetcommunications node. However, when receiving the handover request, thetarget communications node may reject the handover request because theload of the target cell is excessively heavy. In this way, a previousprocess that the UE performs measurement and reporting, a process thatthe source communications node receives and analyzes the measurementresult, and a process of interactions between the source communicationsnode and the target communications node become invalid work. Especially,when the target cell is deployed in a hotspot area, because of arelatively large quantity of UEs, a very large amount of invalid work iscaused. FIG. 2 is a schematic diagram of a target cell rejecting accessby UE because load of the target cell is excessively heavy.

The foregoing invalid work increases unnecessary signaling overheadbetween the UE and the source communications node and between the sourcecommunications node and the target communications node, and increases arunning burden of analyzing the measurement result by the sourcecommunications node; moreover, because the source cell cannot performscheduling for the UE in a measurement process, normal informationtransmission cannot be performed. The foregoing invalid measurementprocess severely affects a throughput of the UE.

In addition, in the prior art, once a reference signal starts beingsent, a sending state of the reference signal no longer changes.

SUMMARY

Embodiments of the present invention provide a signal transmissionmethod and device, so as to flexibly send a reference signal.

According to a first aspect, a signal transmission method is provided,including: adjusting, by a first communications node, a sending state ofa reference signal of a cell that belongs to the first communicationsnode; and sending, by the first communications node, the referencesignal of the cell according to an adjusted sending state of thereference signal.

With reference to the first aspect, in a first possible implementationmanner, the adjusting, by a first communications node, a sending stateof a reference signal of a cell that belongs to the first communicationsnode includes: adjusting, by the first communications node, the sendingstate of the reference signal to be stopping sending the referencesignal of the cell; and the sending, by the first communications node,the reference signal of the cell according to an adjusted sending stateof the reference signal includes: stopping, by the first communicationsnode, sending the reference signal of the cell; or

the adjusting, by a first communications node, a sending state of areference signal of a cell that belongs to the first communications nodeincludes: lowering, by the first communications node, a sending power ofsending the reference signal of the cell; and the sending, by the firstcommunications node, the reference signal of the cell according to anadjusted sending state of the reference signal includes: sending, by thefirst communications node, the reference signal by using a loweredsending power; or

the adjusting, by a first communications node, a sending state of areference signal of a cell that belongs to the first communications nodeincludes: extending, by the first communications node, a sending periodof sending the reference signal of the cell; and the sending, by thefirst communications node, the reference signal of the cell according toan adjusted sending state of the reference signal includes: sending, bythe first communications node, the reference signal by using a extendedsending period; or

the adjusting, by a first communications node, a sending state of areference signal of a cell that belongs to the first communications nodeincludes: lowering, by the first communications node, a bandwidthoccupied when the reference signal of the cell is sent; and the sending,by the first communications node, the reference signal of the cellaccording to an adjusted sending state of the reference signal includes:sending, by the first communications node, the reference signal by usinga lowered bandwidth.

With reference to the first aspect, or the first possible implementationmanner of the first aspect, in a second possible implementation manner,before the adjusting, by a first communications node, a sending state ofa reference signal of a cell that belongs to the first communicationsnode, the method further includes: determining, by the firstcommunications node, that the sending state of the reference signal ofthe cell needs to be adjusted.

With reference to the second possible implementation manner of the firstaspect, in a third possible implementation manner, the determining, bythe first communications node, that the sending state of the referencesignal of the cell needs to be adjusted includes: when one or more ofthe following cases occur in the cell, determining, by the firstcommunications node, that the sending state of the reference signalneeds to be adjusted: a radio resource is overloaded; a backhaul linknetwork is overloaded; a transmission delay in a backhaul link exceeds aset threshold; or a hardware resource is overloaded.

With reference to the first aspect, or the first to third possibleimplementation manners of the first aspect, in a fourth possibleimplementation manner, after the adjusting, by a first communicationsnode, a sending state of a reference signal of a cell that belongs tothe first communications node, the method further includes: sending, bythe first communications node, indication information to acommunications device in the cell, where the indication information isused for indicating at least one of the following indications: anindication that the communications device in the cell determines,according to the adjusted sending state, of the reference signal,indicated by the indication information, whether to measure thereference signal; an indication that the communications device in thecell measures the reference signal according to adjusted measurementconfiguration information indicated by the indication information; anindication that the communications device in the cell no longer measuresthe reference signal; or an indication that the communications device inthe cell measures a set type of reference signals, where the set type isdifferent from a type of the adjusted reference signal.

With reference to the fourth possible implementation manner of the firstaspect, in a fifth possible implementation manner, the sending, by thefirst communications node, indication information to a communicationsdevice in the cell includes at least one of the following: broadcasting,by the first communications node, the indication information to thecommunications device in the cell by using a system information blockSIB; sending the indication information to the communications device inthe cell by using dedicated radio resource control RRC signaling;broadcasting the indication information to the communications device inthe cell by using a physical layer broadcast message; or sending theindication information to the communications device in the cell by usingdownlink control information DCI.

With reference to the first aspect, or the first to fifth possibleimplementation manners of the first aspect, in a sixth possibleimplementation manner, after the adjusting, by a first communicationsnode, a sending state of a reference signal of a cell that belongs tothe first communications node, the method further includes: notifying,by the first communications node, the communications device in the cellto receive data and/or control signaling on a resource carrying thereference signal.

With reference to the sixth possible implementation manner of the firstaspect, in a seventh possible implementation manner, the firstcommunications node notifies, according to at least one of the followingmanners, the communications device in the cell to receive the dataand/or control signaling on the resource carrying the reference signal:notifying, by the first communications node by using a systeminformation block SIB, the communications device in the cell to receivethe data and/or control signaling on the resource carrying the referencesignal; notifying, by the first communications node by using dedicatedradio resource control RRC signaling, the communications device in thecell to receive the data and/or control signaling on the resourcecarrying the reference signal; notifying, by the first communicationsnode by using a physical layer broadcast message, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal; or notifying, by the firstcommunications node by using downlink control information DCI, thecommunications device in the cell to receive the data and/or controlsignaling on the resource carrying the reference signal.

With reference to the sixth or seventh possible implementation manner ofthe first aspect, in an eighth possible implementation manner, after thefirst communications node notifies the communications device in the cellto receive the control signaling on the resource carrying the referencesignal, the first communications node sends, by using a physical layercontrol channel, the control signaling on the resource carrying thereference signal to the communications device in the cell; and/or, afterthe first communications node notifies the communications device in thecell to receive the data on the resource occupied when the referencesignal is carried, the first communications node sends, by using aphysical layer data channel, the data on the resource carrying thereference signal to the communications device in the cell.

With reference to the first aspect, or the first to eighth possibleimplementation manners of the first aspect, in a ninth possibleimplementation manner, after the adjusting, by a first communicationsnode, a sending state of a reference signal of a cell, the methodfurther includes: notifying, by the first communications node, acommunications node of a neighboring cell of the adjusted sending stateof the reference signal of the cell, to enable the communications nodeof the neighboring cell to determine, according to the adjusted sendingstate of the reference signal of the cell, whether UE in the neighboringcell needs to measure the cell, and/or, determine configurationinformation for measuring the cell by UE in the neighboring cell.

With reference to the first aspect, or the first to ninth possibleimplementation manners of the first aspect, in a tenth possibleimplementation manner, after the adjusting, by a first communicationsnode, a sending state of a reference signal of a cell that belongs tothe first communications node, the method further includes: after thefirst communications node determines that the reference signal needs tobe sent, sending, by the first communications node, the reference signalincluding load information of the cell.

With reference to the tenth possible implementation manner of the firstaspect, in an eleventh possible implementation manner, the sending, bythe first communications node, the reference signal including loadinformation of the cell includes at least one of the following: sending,by the first communications node, the reference signal according to areference signal sending period corresponding to the load information;sending, by the first communications node, the reference signalincluding encoding information corresponding to the load information; orsending, by the first communications node, the reference signal by usinga bandwidth corresponding to the load information.

With reference to the first aspect, or the first to eleventh possibleimplementation manners of the first aspect, in a twelfth possibleimplementation manner, the adjusting, by a first communications node, asending state of a reference signal of a cell that belongs to the firstcommunications node includes: adjusting, by the first communicationsnode, the sending state of the reference signal of the cell by using acommunications device managed by the first communications node; oradjusting, by a physical layer of the first communications node, thesending state of the reference signal according to an adjustment mannerindicated by a radio resource control RRC layer of the firstcommunications node.

With reference to the first aspect, or the first to twelfth possibleimplementation manners of the first aspect, in a thirteenth possibleimplementation manner, after the adjusting, by a first communicationsnode, a sending state of a reference signal of a cell that belongs tothe first communications node, the method further includes: after thefirst communications node determines that the sending state of thereference signal needs to be restored, restoring the sending state ofthe reference signal, and sending the reference signal by using arestored sending state.

With reference to the first aspect, or the first to thirteenth possibleimplementation manners of the first aspect, in a fourteenth possibleimplementation manner, the reference signal is at least one of thefollowing types of reference signals: a synchronization signal; adiscovery reference signal Discovery RS; a channel state informationreference signal CSI-RS;

a cell-specific reference signal CRS; a common demodulation referencesignal DM-RS; or a cell-common reference signal.

According to a second aspect, a signal transmission method is provided,including: receiving, by a communications device, an adjusted referencesignal, of a cell in which the communications device is located, sent bya first communications node; and performing, by the communicationsdevice, communication according to the adjusted reference signal, wherethe reference signal is: the reference signal sent by the firstcommunications node according to an adjusted sending state of thereference signal.

With reference to the second aspect, in a first possible implementationmanner, before the receiving, by a communications device, an adjustedreference signal, of a cell in which the communications device islocated, sent by a first communications node, the method furtherincludes: receiving, by the communications device, indicationinformation sent by the first communications node, where the indicationinformation is used for indicating the sending state, of the referencesignal, adjusted by the first communications node; and adjusting, by thecommunications device, measurement of the reference signal according tothe adjusted sending state of the reference signal.

With reference to the first possible implementation manner of the secondaspect, in a second possible implementation manner, the adjusting, bythe communications device, measurement of the reference signal accordingto the adjusted sending state, of the reference signal, indicated by theindication information includes at least one of the following:

determining, by the communications device according to the adjustedsending state, of the reference signal, indicated by the indicationinformation, whether to measure the reference signal; measuring, by thecommunications device, the reference signal according to adjustedmeasurement configuration information indicated by the indicationinformation; no longer measuring, by the communications device, thereference signal according to an indication, of no longer measuring thereference signal, in the indication information; and measuring, by thecommunications device, a first type of reference signals according to anindication, of measuring the first type of reference signals, in theindication information, where the first type is different from a type ofthe adjusted reference signal.

With reference to the first or second possible implementation manner ofthe second aspect, in a third possible implementation manner, thereceiving, by the communications device, indication information sent bythe first communications node includes at least one of the following:receiving, by the communications device by using a system informationblock SIB, the indication information sent by a communications node ofthe cell in which the communications device is located; receiving, byusing dedicated radio resource control RRC signaling, the indicationinformation sent by a communications node of the cell in which thecommunications device is located; receiving, by using a physical layerbroadcast message, the indication information sent by a communicationsnode of the cell in which the communications device is located; orreceiving, by using downlink control information DCI, the indicationinformation sent by a communications node of the cell in which thecommunications device is located.

According to a third aspect, a signal transmission method is provided,including: receiving, by a communications device, notificationinformation sent by a first communications node, where the notificationinformation is sent by the first communications node after the firstcommunications node adjusts a sending state of a reference signal of acell in which the communications device is located; and receiving, bythe communications device according to the notification information,data and/or control signaling on a resource carrying the referencesignal.

With reference to the third aspect, in a first possible implementationmanner, the receiving, by the communications device, data and/or controlsignaling on a resource carrying the reference signal includes:receiving, by the communications device by using a physical layercontrol channel, the control signaling on the resource carrying thereference signal; and/or, receiving, by using a physical layer datachannel, the data on the resource carrying the reference signal.

With reference to the third aspect, in a second possible implementationmanner, the receiving, by a communications device, notificationinformation sent by a first communications node includes at least one ofthe following: receiving, by the communications device by using a systeminformation block SIB, the notification information sent by the firstcommunications node; receiving, by using dedicated radio resourcecontrol RRC signaling, the notification information sent by the firstcommunications node; receiving, by using a physical layer broadcastmessage, the notification information sent by the first communicationsnode; or receiving, by using downlink control information DCI, thenotification information sent by the first communications node.

According to a fourth aspect, a signal transmission method is provided,including: receiving, by a first communications node, an adjustedsending state, of a reference signal of a neighboring cell, sent by acommunications node of the neighboring cell; and controlling, by thefirst communications node according to the received adjusted sendingstate of the reference signal of the neighboring cell, measurement of acell of user equipment UE served by the first communications node.

With reference to the fourth aspect, in a first possible implementationmanner, the controlling, by the first communications node according tothe received adjusted sending state of the reference signal of theneighboring cell, measurement of a cell of user equipment UE served bythe first communications node includes: determining, by the firstcommunications node according to the received adjusted sending state ofthe reference signal of the neighboring cell, whether the UE served bythe first communications node needs to measure the neighboring cell,and/or, determining configuration information for measuring theneighboring cell by UE served by the first communications node.

According to a fifth aspect, a signal transmission method is provided,including: generating, by a first communications node, a referencesignal, where the reference signal carries load information of a cell inwhich the first communications node is located; and sending, by thefirst communications node, the reference signal, where the referencesignal is used for enabling a communications device that detects thereference signal to determine, according to the load information,whether to measure the cell, or determine whether to report ameasurement result of measuring the cell, or determine whether to accessthe cell.

With reference to the fifth aspect, in a first possible implementationmanner, the sending, by the first communications node, the referencesignal includes at least one of the following: sending, by the firstcommunications node, the reference signal according to a referencesignal sending period corresponding to the load information; sending, bythe first communications node, the reference signal including encodinginformation corresponding to the load information; or sending, by thefirst communications node, the reference signal by using a bandwidthcorresponding to the load information.

According to a sixth aspect, a signal transmission method is provided,where the method includes: receiving, by a communications device, areference signal sent by a first communications node, where thereference signal carries load information of a cell in which the firstcommunications node is located; and determining, by the communicationsdevice according to the load information, whether to measure the cell,or determining whether to report a measurement result of measuring thecell, or determining whether to access the cell.

With reference to the sixth aspect, in a first possible implementationmanner, before the determining, by the communications device accordingto the load information, whether to measure the cell, or determiningwhether to report a measurement result of measuring the cell, ordetermining whether to access the cell, the method further includes atleast one of the following: determining, by the communications deviceaccording to a reference signal sending period of sending the referencesignal by the first communications node, the load information includedin the reference signal; determining the load information according toencoding information included in the reference signal; or determiningthe load information according to a bandwidth occupied when the firstcommunications node sends the reference signal.

According to a seventh aspect, a signal transmission device is provided,including: an adjustment module, configured to adjust a sending state ofa reference signal of a cell that belongs to a first communications nodein which the adjustment module is located, and transmit an adjustedsending state of the reference signal to a sending module; and thesending module, configured to receive the sending state, of thereference signal, adjusted by the adjustment module, and send thereference signal of the cell according to the adjusted sending state ofthe reference signal.

With reference to the seventh aspect, in a first possible implementationmanner, the adjustment module is specifically configured to: adjust thesending state of the reference signal to be stopping sending thereference signal of the cell; and the sending module is specificallyconfigured to: stop sending the reference signal of the cell; or theadjustment module is specifically configured to: lower a sending powerof sending the reference signal of the cell; and the sending module isspecifically configured to: send the reference signal by using thelowered sending power; or the adjustment module is specificallyconfigured to: extend a sending period of sending the reference signalof the cell; and the sending module is specifically configured to: sendthe reference signal by using the extended sending period; or theadjustment module is specifically configured to: lower a bandwidthoccupied when the reference signal of the cell is sent; and the sendingmodule is specifically configured to: send the reference signal by usingthe lowered bandwidth.

With reference to the seventh aspect, or the first possibleimplementation manner of the seventh aspect, in a second possibleimplementation manner, the device further includes: a determiningmodule, configured to: before the adjustment module adjusts the sendingstate of the reference signal, determine that the sending state of thereference signal of the cell needs to be adjusted.

With reference to the second possible implementation manner of theseventh aspect, in a third possible implementation manner, thedetermining module is specifically configured to: when one or more ofthe following cases occur in the cell, determine that the sending stateof the reference signal needs to be adjusted: a radio resource isoverloaded; a backhaul link network is overloaded; a transmission delayin a backhaul link exceeds a set threshold; or a hardware resource isoverloaded.

With reference to the seventh aspect, or the first to third possibleimplementation manners of the seventh aspect, in a fourth possibleimplementation manner, the sending module is further configured to:after the adjustment module adjusts the sending state of the referencesignal of the cell, send indication information to a communicationsdevice in the cell, where the indication information is used forindicating at least one of the following indications: an indication thatthe communications device in the cell determines, according to theadjusted sending state, of the reference signal, indicated by theindication information, whether to measure the reference signal; anindication that the communications device in the cell measures thereference signal according to adjusted measurement configurationinformation indicated by the indication information; an indication thatthe communications device in the cell no longer measures the referencesignal; or an indication that the communications device in the cellmeasures a set type of reference signals, where the set type isdifferent from a type of the adjusted reference signal.

With reference to the fourth possible implementation manner of theseventh aspect, in a fifth possible implementation manner, the sendingmodule is specifically configured to send the indication informationaccording to at least one of the following: broadcasting the indicationinformation to the communications device in the cell by using a systeminformation block SIB; sending the indication information to thecommunications device in the cell by using dedicated radio resourcecontrol RRC signaling; broadcasting the indication information to thecommunications device in the cell by using a physical layer broadcastmessage; or sending the indication information to the communicationsdevice in the cell by using downlink control information DCI.

With reference to the seventh aspect, or the first to fifth possibleimplementation manners of the seventh aspect, in a sixth possibleimplementation manner, the sending module is further configured to:after the adjustment module adjusts the sending state of the referencesignal of the cell, notify the communications device in the cell toreceive data and/or control signaling on a resource carrying thereference signal.

With reference to the sixth possible implementation manner of theseventh aspect, in a seventh possible implementation manner, the sendingmodule is specifically configured to notify, according to at least oneof the following manners, the communications device in the cell toreceive the data and/or control signaling on the resource carrying thereference signal: notifying, by using a system information block SIB,the communications device in the cell to receive the data and/or controlsignaling on the resource carrying the reference signal; notifying, byusing dedicated radio resource control RRC signaling, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal; notifying, by using a physicallayer broadcast message, the communications device in the cell toreceive the data and/or control signaling on the resource carrying thereference signal; or notifying, by using downlink control informationDCI, the communications device in the cell to receive the data and/orcontrol signaling on the resource carrying the reference signal.

With reference to the sixth or seventh possible implementation manner ofthe seventh aspect, in an eighth possible implementation manner, thesending module is specifically configured to: after the communicationsdevice in the cell is notified to receive the control signaling on theresource carrying the reference signal, send, by using a physical layercontrol channel, the control signaling on the resource carrying thereference signal to the communications device in the cell; and/or afterthe communications device in the cell is notified to receive the data onthe resource occupied when the reference signal is carried, send, byusing a physical layer data channel, the data on the resource carryingthe reference signal to the communications device in the cell.

With reference to the seventh aspect, or the first to eighth possibleimplementation manners of the seventh aspect, in a ninth possibleimplementation manner, the sending module is further configured to:after the adjustment module adjusts the sending state of the referencesignal of the cell, notify a communications node of a neighboring cellof the adjusted sending state of the reference signal of the cell, toenable the communications node of the neighboring cell to determine,according to the adjusted sending state of the reference signal of thecell, whether UE in the neighboring cell needs to measure the cell,and/or, determine configuration information for measuring the cell by UEin the neighboring cell.

With reference to the seventh aspect, or the first to ninth possibleimplementation manners of the seventh aspect, in a tenth possibleimplementation manner, the sending module is further configured to:after the adjustment module adjusts the sending state of the referencesignal of the cell that belongs to the first communications node, sendthe reference signal including load information of the cell.

With reference to the tenth possible implementation manner of theseventh aspect, in an eleventh possible implementation manner, thesending module is specifically configured to send the reference signalaccording to at least one of the following: sending the reference signalaccording to a reference signal sending period corresponding to the loadinformation; sending the reference signal including encoding informationcorresponding to the load information; or sending the reference signalby using a bandwidth corresponding to the load information.

With reference to the seventh aspect, or the first to eleventh possibleimplementation manners of the seventh aspect, in a twelfth possibleimplementation manner, the adjustment module is specifically configuredto: adjust the sending state of the reference signal of the cell byusing a communications device managed by the first communications node;or adjust the sending state of the reference signal according to anadjustment manner indicated by a radio resource control RRC layer of thefirst communications node.

With reference to the seventh aspect, or the first to twelfth possibleimplementation manners of the seventh aspect, in a thirteenth possibleimplementation manner, the adjustment module is further configured to:after it is determined that the sending state of the reference signalneeds to be restored, restore the sending state of the referencesignal,; and the sending module is further configured to: send thereference signal by using a restored sending state.

With reference to the seventh aspect, or the first to thirteenthpossible implementation manners of the seventh aspect, in a fourteenthpossible implementation manner, the reference signal is at least one ofthe following types of reference signals: a synchronization signal; adiscovery reference signal Discovery RS; a channel state informationreference signal CSI-RS; a cell-specific reference signal CRS; a commondemodulation reference signal DM-RS; or a cell-common reference signal.

According to an eighth aspect, a communications device for performingsignal transmission is provided, including: a receiving module,configured to receive an adjusted reference signal, of a cell in whichthe communications device is located, sent by a first communicationsnode, and transmit the adjusted reference signal to a communicationsmodule; and the communications module, configured to receive theadjusted reference signal, of the cell, transmitted by the receivingmodule, and perform communication according to the adjusted referencesignal, where the reference signal is: the reference signal sent by thefirst communications node according to an adjusted sending state of thereference signal.

With reference to the eighth aspect, in a first possible implementationmanner, the receiving module is further configured to: receiveindication information sent by the first communications node, where theindication information is used for indicating the sending state, of thereference signal, adjusted by the first communications node; and thecommunications device further includes: a measurement adjustment module,configured to adjust measurement of the reference signal according tothe adjusted sending state of the reference signal.

With reference to the first possible implementation manner of the eighthaspect, in a second possible implementation manner, the measurementadjustment module is specifically configured to: determine, according tothe adjusted sending state, of the reference signal, indicated by theindication information, whether to measure the reference signal; measurethe reference signal according to adjusted measurement configurationinformation indicated by the indication information; no longer measurethe reference signal according to an indication, of no longer measuringthe reference signal, in the indication information; and measure a firsttype of reference signals according to an indication, of measuring thefirst type of reference signals, in the indication information, wherethe first type is different from a type of the adjusted referencesignal.

With reference to the first or second possible implementation manner ofthe eighth aspect, in a third possible implementation manner, thereceiving module is specifically configured to: receive, by using asystem information block SIB, the indication information sent by acommunications node of the cell in which the communications device islocated; receive, by using dedicated radio resource control RRCsignaling, the indication information sent by a communications node ofthe cell in which the communications device is located; receive, byusing a physical layer broadcast message, the indication informationsent by a communications node of the cell in which the communicationsdevice is located; or receive, by using downlink control informationDCI, the indication information sent by a communications node of thecell in which the communications device is located.

According to a ninth aspect, a communications device for performingsignal transmission is provided, including: a first receiving module,configured to receive notification information sent by a firstcommunications node, and transmit the received notification informationto a second receiving module, where the notification information is sentby the first communications node after the first communications nodeadjusts a sending state of a reference signal of a cell in which thecommunications device is located; and the second receiving module,configured to receive the notification information transmitted by thefirst receiving module, and receive, according to the notificationinformation, data and/or control signaling on a resource carrying thereference signal.

With reference to the ninth aspect, in a first possible implementationmanner, the second receiving module is specifically configured to:receive, by using a physical layer control channel, the controlsignaling on the resource carrying the reference signal; and/or,receive, by using a physical layer data channel, the data on theresource carrying the reference signal.

With reference to the ninth aspect, or the first possible implementationmanner of the ninth aspect, in a second possible implementation manner,the first receiving module is specifically configured to receive, in atleast one of the following manners, the notification information sent bythe first communications node: receiving, by using a system informationblock SIB, the notification information sent by the first communicationsnode; receiving, by using dedicated radio resource control RRCsignaling, the notification information sent by the first communicationsnode; receiving, by using a physical layer broadcast message, thenotification information sent by the first communications node; orreceiving, by using downlink control information DCI, the notificationinformation sent by the first communications node.

According to a tenth aspect, a signal transmission device is provided,including: a receiving module, configured to receive an adjusted sendingstate, of a reference signal of a neighboring cell, sent by acommunications node of the neighboring cell, and transmit the receivedadjusted sending state of the reference signal of the neighboring cellto a control module; and the control module, configured to control,according to the adjusted sending state, of the reference signal of theneighboring cell, transmitted by the receiving module, measurement of acell of user equipment UE served by the device.

With reference to the tenth aspect, in a first possible implementationmanner, the control module is specifically configured to: determine,according to the adjusted sending state, of the reference signal of theneighboring cell, received by the receiving module, whether the UEserved by the device needs to measure the neighboring cell, and/or,determine configuration information for measuring the neighboring cellby the UE served by the device.

According to an eleventh aspect, a signal transmission device isprovided, including: a generation module, configured to generate areference signal of a cell in which a first communications node islocated, and transmit the generated reference signal to a sendingmodule, where the reference signal carries load information of the cellin which the first communications node is located; and the sendingmodule, configured to receive the reference signal generated by thegeneration module, and send the reference signal, where the referencesignal is used for enabling a communications device that detects thereference signal to determine, according to the load information,whether to measure the cell, or determine whether to report ameasurement result of measuring the cell, or determine whether to accessthe cell.

With reference to the eleventh aspect, in a first possibleimplementation manner, the sending module is specifically configured tosend the reference signal according to at least one of the following:

sending the reference signal according to a reference signal sendingperiod corresponding to the load information; sending the referencesignal including encoding information corresponding to the loadinformation; or sending the reference signal by using a bandwidthcorresponding to the load information.

According to a twelfth aspect, a communications device for performingsignal transmission is provided, where the communications deviceincludes: a receiving module, configured to receive a reference signalsent by a first communications node, where the reference signal carriesload information of a cell in which the first communications node islocated, and transmit the received reference signal to a judging module;and the judging module, configured to receive the reference signalreceived by the receiving module, and determine, according to the loadinformation, whether to measure the cell, or determine whether to reporta measurement result of measuring the cell, or determine whether toaccess the cell.

With reference to the twelfth aspect, in a first possible implementationmanner, the judging module is specifically configured to determine theload information according to at least one of the following:

determining, according to a reference signal sending period, of thereference signal, sent by the first communications node, the loadinformation included in the reference signal;

determining the load information according to encoding informationincluded in the reference signal; or

determining the load information according to a bandwidth occupied whenthe first communications node sends the reference signal.

By means of the embodiments of the present invention, a firstcommunications node can adjust a sending state of a reference signal ofa cell that belongs to the first communications node, and send thereference signal according to an adjusted sending state, so that thereference signal can be flexibly sent, thereby enhancing flexibility ofa system.

By means of the embodiments of the present invention, after a firstcommunications node adjusts a sending state of a reference signal of acell in which a communications device is located, the communicationsdevice can use resource reception information released from thereference signal after the sending state is adjusted, so that networkresources can be fully used, thereby increasing network utilization.

By means of the embodiments of the present invention, after acommunications node of a neighboring cell sends an adjusted sendingstate of a reference signal of the neighboring cell, a firstcommunications node can control, according to the adjusted sendingstate, measurement of a cell of user equipment UE served by the firstcommunications node, thereby increasing measurement efficiency of theUE.

By means of the embodiments of the present invention, a firstcommunications node adds load information to a reference signal, so thata communications device that receives the reference signal can perform acorresponding operation according to the load information, therebypreventing the communications device from accessing a cell with highload.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of UE being handed over between differentcells in a heterogeneous network;

FIG. 2 is a schematic diagram of a target cell rejecting access by UEbecause load of the target cell is excessively heavy;

FIG. 3 is a schematic structural diagram of a signal transmission deviceaccording to Embodiment 1 of the present invention;

FIG. 4 is a schematic structural diagram of a communications device forperforming signal transmission according to Embodiment 2 of the presentinvention;

FIG. 5 is a schematic structural diagram of a communications device forperforming signal transmission according to Embodiment 3 of the presentinvention;

FIG. 6 is a schematic structural diagram of a signal transmission deviceaccording to Embodiment 4 of the present invention;

FIG. 7 is a schematic structural diagram of a signal transmission deviceaccording to Embodiment 5 of the present invention;

FIG. 8 is a schematic structural diagram of a communications device forperforming signal transmission according to Embodiment 6 of the presentinvention;

FIG. 9 is a structural diagram of a signal transmission device accordingto Embodiment 7 of the present invention;

FIG. 10 is a structural diagram of a communications device forperforming signal transmission according to Embodiment 8 of the presentinvention;

FIG. 11 is a structural diagram of a communications device forperforming signal transmission according to Embodiment 9 of the presentinvention;

FIG. 12 is a structural diagram of a signal transmission deviceaccording to Embodiment 10 of the present invention;

FIG. 13 is a structural diagram of a signal transmission deviceaccording to Embodiment 11 of the present invention;

FIG. 14 is a structural diagram of a communications device forperforming signal transmission according to Embodiment 12 of the presentinvention;

FIG. 15 is a flowchart of a signal transmission method according toEmbodiment 1 of the present invention;

FIG. 16 is a schematic diagram of assisted transmission of backhaulnetwork data between base stations according to an embodiment of thepresent invention;

FIG. 17 is a flowchart of a signal transmission method according toEmbodiment 2 of the present invention;

FIG. 18 is a flowchart of a signal transmission method according toEmbodiment 3 of the present invention;

FIG. 19 is a flowchart of a signal transmission method according toEmbodiment 4 of the present invention;

FIG. 20 is a flowchart of a signal transmission method according toEmbodiment 5 of the present invention;

FIG. 21 is a flowchart of a signal transmission method according toEmbodiment 6 of the present invention;

FIG. 22 is a flowchart of a signal transmission method according toImplementation Manner 1 of the present invention;

FIG. 23 is a flowchart of a signal transmission method according toImplementation Manner 2 of the present invention;

FIG. 24 is a flowchart of a signal transmission method according toImplementation Manner 3 of the present invention;

FIG. 25 is a schematic diagram of notifying UE in a target cell of thatsending of a reference signal is stopped after a first communicationsnode has over load (over load);

FIG. 26 is a flowchart of a signal transmission method according toImplementation Manner 4 of the present invention; and

FIG. 27 is a flowchart of a signal transmission method according toImplementation Manner 5 of the present invention.

DETAILED DESCRIPTION

To make the objectives, technical solutions, and advantages of theembodiments of the present invention clearer, the following clearlydescribes the technical solutions in the embodiments of the presentinvention with reference to the accompanying drawings in the embodimentsof the present invention. Apparently, the described embodiments are somebut not all of the embodiments of the present invention. All otherembodiments obtained by a person of ordinary skill in the art based onthe embodiments of the present invention without creative efforts shallfall within the protection scope of the present invention. Forembodiments below, reference may be made to each other without anycontradiction.

The technical solutions described in the embodiments of the presentinvention may be applied to various communications systems, such ascurrent 2G and 3G communications systems and a next-generationcommunications system, for example, a Global System for MobileCommunications (GSM, Global System for Mobile communications), a CodeDivision Multiple Access (CDMA, Code Division Multiple Access) system, aTime Division Multiple Access (TDMA, Time Division Multiple Access)system, a Wideband Code Division Multiple Access (WCDMA, Wideband CodeDivision Multiple Access) system, a Frequency Division Multiple Access(FDMA, Frequency Division Multiple Access) system, an OrthogonalFrequency-Division Multiple Access (OFDMA, Orthogonal Frequency-DivisionMultiple Access) system, a single-carrier FDMA (SC-FDMA) system, aGeneral Packet Radio Service (GPRS, General Packet Radio Service)system, a Long Term Evolution (LTE, Long Term Evolution) system, andother similar communications systems.

In the embodiments of the present invention, various aspects of thetechnical solutions are described from the perspective of user equipmentand/or a base station.

The user equipment may be a wireless terminal or a wired terminal. Thewireless terminal may refer to a device that provides a user with voiceand/or data connectivity, a handheld device with a radio connectionfunction, or another processing device connected to a radio modem. Thewireless terminal may communicate with one or more core networks byusing a radio access network (such as RAN, Radio Access Network). Thewireless terminal may be a mobile terminal, such as a mobile phone (alsoreferred to as a “cellular” phone) and a computer with a mobileterminal, for example, may be a portable, pocket-sized, handheld,computer built-in, or in-vehicle mobile device, which exchanges voiceand/or data with the radio access network. For example, it may be adevice such as a personal communication service (PCS, PersonalCommunication Service) phone, a cordless telephone set, a SessionInitiation Protocol (SIP) phone, a wireless local loop (WLL, WirelessLocal Loop) station, or a personal digital assistant (PDA, PersonalDigital Assistant). The wireless terminal may also be called a system, asubscriber unit (Subscriber Unit), a subscriber station (SubscriberStation), a mobile station (Mobile Station), a mobile terminal (Mobile),a remote station (Remote Station), an access point (Access Point), aremote terminal (Remote Terminal), an access terminal (Access Terminal),a user terminal (User Terminal), a user agent (User Agent), a userdevice (User Device), or user equipment (User Equipment).

The base station (for example, an access point) may refer to a device incommunication with a wireless terminal via one or more sectors at an airinterface in an access network. The base station may be configured tomutually convert a received over-the-air frame and an IP packet andserve as a router between the wireless terminal and a rest portion ofthe access network, where the rest portion of the access network mayinclude an Internet protocol (IP) network. The base station may alsocoordinate attribute management of the air interface. For example, thebase station may be an evolved NodeB (NodeB, eNB, or e-NodeB, evolvedNode B) in LTE, or may be a base transceiver station (BTS, BaseTransceiver Station) in GSM or CDMA, or may be a NodeB (NodeB) in WCDMA,which is not limited in the this application.

A base station processor may be a base station controller (BSC, basestation controller) in GSM or CDMA, or a radio network controller (RNC,Radio Network Controller) in WCDMA, which is not limited in thisapplication.

In addition, the terms “system” and “network” may be usedinterchangeably in the embodiments of the present invention. The term“and/or” in the embodiments of the present invention describes only anassociation relationship for describing associated objects andrepresents that three relationships may exist. For example, A and/or Bmay represent the following three cases: Only A exists, both A and Bexist, and only B exists. In addition, the character “/” in theembodiments of the present invention generally indicates an “or”relationship between associated objects.

FIG. 3 is a schematic structural diagram of a signal transmission deviceaccording to Embodiment 1 of the present invention, where the signaltransmission device includes:

an adjustment module 31, configured to adjust a sending state of areference signal of a cell that belongs to a first communications nodein which the adjustment module 31 is located, and transmit an adjustedsending state of the reference signal to a sending module 32; and

the sending module 32, configured to receive the sending state, of thereference signal, adjusted by the adjustment module 31, and send thereference signal of the cell according to the adjusted sending state ofthe reference signal.

Preferably, the adjustment module 31 is specifically configured to:adjust the sending state of the reference signal to be stopping sendingthe reference signal of the cell; and the sending module 32 isspecifically configured to: stop sending the reference signal of thecell; or, the adjustment module 31 is specifically configured to: lowera sending power of sending the reference signal of the cell; and thesending module 32 is specifically configured to: send the referencesignal by using the lowered sending power; or, the adjustment module 31is specifically configured to: extend a sending period of sending thereference signal of the cell; and the sending module 32 is specificallyconfigured to: send the reference signal by using the extended sendingperiod; or the adjustment module 31 is specifically configured to: lowera bandwidth occupied when the reference signal of the cell is sent; andthe sending module 32 is specifically configured to: send the referencesignal by using the lowered bandwidth.

Preferably, the device further includes:

a determining module 33, configured to: before the adjustment module 31adjusts the sending state of the reference signal, determine that thesending state of the reference signal of the cell needs to be adjusted.

Preferably, the determining module 33 is specifically configured to:

when one or more of the following cases occur in the cell, determinethat the sending state of the reference signal needs to be adjusted:

a radio resource is overloaded;

a backhaul link network is overloaded;

a transmission delay in a backhaul link exceeds a set threshold; or

a hardware resource is overloaded.

Preferably, the sending module 32 is further configured to:

after the adjustment module 31 adjusts the sending state of thereference signal of the cell, send indication information to acommunications device in the cell, where the indication information isused for indicating at least one of the following indications:

an indication that the communications device in the cell determines,according to the adjusted sending state, of the reference signal,indicated by the indication information, whether to measure thereference signal;

an indication that the communications device in the cell measures thereference signal according to adjusted measurement configurationinformation indicated by the indication information;

an indication that the communications device in the cell no longermeasures the reference signal; or

an indication that the communications device in the cell measures a settype of reference signals, where the set type is different from a typeof the adjusted reference signal.

Preferably, the sending module 32 is specifically configured to send theindication information according to at least one of the following:

broadcasting the indication information to the communications device inthe cell by using a system information block SIB; sending the indicationinformation to the communications device in the cell by using dedicatedradio resource control RRC signaling; broadcasting the indicationinformation to the communications device in the cell by using a physicallayer broadcast message; or sending the indication information to thecommunications device in the cell by using downlink control informationDCI.

Preferably, the sending module 32 is further configured to:

after the adjustment module 31 adjusts the sending state of thereference signal of the cell, notify the communications device in thecell to receive data and/or control signaling on a resource carrying thereference signal.

Preferably, the sending module 32 is specifically configured to notify,according to at least one of the following manners, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal:

notifying, by using a system information block SIB, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal;

notifying, by using dedicated radio resource control RRC signaling, thecommunications device in the cell to receive the data and/or controlsignaling on the resource carrying the reference signal;

notifying, by using a physical layer broadcast message, thecommunications device in the cell to receive the data and/or controlsignaling on the resource carrying the reference signal; or

notifying, by using downlink control information DCI, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal.

Preferably, the sending module 32 is specifically configured to:

after the communications device in the cell is notified to receive thecontrol signaling on the resource carrying the reference signal, send,by using a physical layer control channel, the control signaling on theresource carrying the reference signal to the communications device inthe cell; and/or

after the communications device in the cell is notified to receive thedata on the resource occupied when the reference signal is carried,send, by using a physical layer data channel, the data on the resourcecarrying the reference signal to the communications device in the cell.

Preferably, the sending module 32 is further configured to: after theadjustment module 31 adjusts the sending state of the reference signalof the cell,

notify a communications node of a neighboring cell of the adjustedsending state of the reference signal of the cell, to enable thecommunications node of the neighboring cell to determine, according tothe adjusted sending state of the reference signal of the cell, whetherUE in the neighboring cell needs to measure the cell, and/or, determineconfiguration information for measuring the cell by UE in theneighboring cell.

Preferably, the sending module 32 is further configured to: after theadjustment module 31 adjusts the sending state of the reference signalof the cell that belongs to the first communications node, send thereference signal including load information of the cell.

Preferably, the sending module 32 is specifically configured to:

send the reference signal according to a reference signal sending periodcorresponding to the load information;

send the reference signal including encoding information correspondingto the load information; or

send the reference signal by using a bandwidth corresponding to the loadinformation.

Preferably, the adjustment module 31 is specifically configured to:

adjust the sending state of the reference signal of the cell by using acommunications device managed by the first communications node; or

adjust the sending state of the reference signal according to anadjustment manner indicated by a radio resource control RRC layer of thefirst communications node.

Preferably, the adjustment module 31 is further configured to:

after it is determined that the sending state of the reference signalneeds to be restored, restore the sending state of the reference signal;and the sending module 32 is further configured to: send the referencesignal by using a restored sending state.

Preferably, the reference signal is at least one of the following typesof reference signals:

a synchronization signal;

a discovery reference signal Discovery RS;

a channel state information reference signal CSI-RS;

a cell-specific reference signal CRS;

a common demodulation reference signal DM-RS; or

a cell-common reference signal.

FIG. 4 is a schematic structural diagram of a communications device forperforming signal transmission according to Embodiment 2 of the presentinvention, where the communications device includes:

a receiving module 41, configured to receive an adjusted referencesignal, of a cell in which the communications device is located, sent bya first communications node, and transmit the adjusted reference signalto a communications module 42; and

the communications module 42, configured to receive the adjustedreference signal, of the cell, transmitted by the receiving module 41,and perform communication according to the adjusted reference signal,where

the reference signal is: the reference signal sent by the firstcommunications node according to an adjusted sending state of thereference signal.

Preferably, the receiving module 41 is further configured to:

receive indication information sent by the first communications node,where the indication information is used for indicating the sendingstate, of the reference signal, adjusted by the first communicationsnode; and

the communications device further includes:

a measurement adjustment module 43, configured to adjust measurement ofthe reference signal according to the adjusted sending state of thereference signal.

Preferably, the measurement adjustment module 43 is specificallyconfigured to:

determine, according to the adjusted sending state, of the referencesignal, indicated by the indication information, whether to measure thereference signal;

measure the reference signal according to adjusted measurementconfiguration information indicated by the indication information;

no longer measure the reference signal according to an indication, of nolonger measuring the reference signal, in the indication information; or

measure a first type of reference signals according to an indication, ofmeasuring the first type of reference signals, in the indicationinformation, where the first type is different from a type of theadjusted reference signal.

Preferably, the receiving module 41 is specifically configured to:

receive, by using a system information block SIB, the indicationinformation sent by a communications node of the cell in which thecommunications device is located; receive, by using dedicated radioresource control RRC signaling, the indication information sent by acommunications node of the cell in which the communications device islocated; receive, by using a physical layer broadcast message, theindication information sent by a communications node of the cell inwhich the communications device is located; or receive, by usingdownlink control information DCI, the indication information sent by acommunications node of the cell in which the communications device islocated.

FIG. 5 is a schematic structural diagram of a communications device forperforming signal transmission according to Embodiment 3 of the presentinvention, where the communications device includes:

a first receiving module 51, configured to receive notificationinformation sent by a first communications node, and transmit thereceived notification information to a second receiving module 52, wherethe notification information is sent by the first communications nodeafter the first communications node adjusts a sending state of areference signal of a cell in which the communications device islocated; and

the second receiving module 52, configured to receive the notificationinformation received by the first receiving module 51, and receive,according to the notification information, data and/or control signalingon a resource carrying the reference signal.

Preferably, the second receiving module 52 is specifically configuredto:

receive, by using a physical layer control channel, the controlsignaling on the resource carrying the reference signal; and/or,receive, by using a physical layer data channel, the data on theresource carrying the reference signal.

Preferably, the first receiving module 51 is specifically configured to:receive, in at least one of the following manners, the notificationinformation sent by the first communications node:

receiving, by using a system information block SIB, the notificationinformation sent by the first communications node; receiving, by usingdedicated radio resource control RRC signaling, the notificationinformation sent by the first communications node; receiving, by using aphysical layer broadcast message, the notification information sent bythe first communications node; or receiving, by using downlink controlinformation DCI, the notification information sent by the firstcommunications node.

FIG. 6 is a schematic structural diagram of a signal transmission deviceaccording to Embodiment 4 of the present invention, where the signaltransmission device includes:

a receiving module 61, configured to receive an adjusted sending state,of a reference signal of a neighboring cell, sent by a communicationsnode of the neighboring cell, and transmit the received adjusted sendingstate of the reference signal of the neighboring cell to a controlmodule 62; and

the control module 62, configured to control, according to the adjustedsending state, of the reference signal of the neighboring cell, receivedby the receiving module 61, measurement of a cell of user equipment UEserved by the device.

Preferably, the control module 62 is specifically configured to:

determine, according to the adjusted sending state, of the referencesignal of the neighboring cell, received by the receiving module 61,whether the UE served by the device needs to measure the neighboringcell, and/or, determine configuration information for measuring theneighboring cell by the UE served by the device.

FIG. 7 is a schematic structural diagram of a signal transmission deviceaccording to Embodiment 5 of the present invention, where the signaltransmission device includes:

a generation module 71, configured to generate a reference signal of acell in which a first communications node is located, and transmit thegenerated reference signal to a sending module 72, where the referencesignal carries load information of the cell in which the firstcommunications node is located; and

the sending module 72, configured to receive the reference signalgenerated by the generation module 71, and send the reference signal,where the reference signal is used for enabling a communications devicethat detects the reference signal to determine, according to the loadinformation, whether to measure the cell, or determine whether to reporta measurement result of measuring the cell, or determine whether toaccess the cell.

Preferably, the sending module 72 is specifically configured to send thereference signal according to at least one of the following:

sending the reference signal according to a reference signal sendingperiod corresponding to the load information;

sending the reference signal including encoding informationcorresponding to the load information; or

sending the reference signal by using a bandwidth corresponding to theload information.

FIG. 8 is a schematic structural diagram of a communications device forperforming signal transmission according to Embodiment 6 of the presentinvention, where the communications device includes:

a receiving module 81, configured to receive a reference signal sent bya first communications node, where the reference signal carries loadinformation of a cell in which the first communications node is located,and transmit the received reference signal to a judging module 82; and

the judging module 82, configured to receive the reference signalreceived by the receiving module 81, and determine, according to theload information, whether to measure the cell, or determine whether toreport a measurement result of measuring the cell, or determine whetherto access the cell.

Preferably, the judging module 82 is specifically configured todetermine the load information according to at least one of thefollowing:

determining, according to a reference signal sending period of sendingthe reference signal by the first communications node, the loadinformation included in the reference signal;

determining the load information according to encoding informationincluded in the reference signal; or

determining the load information according to a bandwidth occupied whenthe first communications node sends the reference signal.

FIG. 9 is a structural diagram of a signal transmission device accordingto Embodiment 7 of the present invention, where the signal transmissiondevice includes:

a processor 91, configured to adjust a sending state of a referencesignal of a cell that belongs to a first communications node in whichthe processor 91 is located, and transmit the adjusted sending state ofthe reference signal to a transmitter 92; and

the transmitter 92, configured to receive the sending state, of thereference signal, adjusted by the processor 91, and send the referencesignal of the cell according to the adjusted sending state of thereference signal.

Preferably, the processor 91 is specifically configured to: adjust thesending state of the reference signal to be stopping sending thereference signal of the cell; and the transmitter 92 is specificallyconfigured to: stop sending the reference signal of the cell; or

the processor 91 is specifically configured to: lower a sending power ofsending the reference signal of the cell; and the transmitter 102 isspecifically configured to: send the reference signal by using thelowered sending power; or

the processor 91 is specifically configured to: extend a sending periodof sending the reference signal of the cell; and the transmitter 102 isspecifically configured to: send the reference signal by using theextended sending period; or

the processor 91 is specifically configured to: lower a bandwidthoccupied when the reference signal of the cell is sent; and thetransmitter 92 is specifically configured to: send the reference signalby using the lowered bandwidth.

Preferably, the processor 91 is further configured to: before thesending state of the reference signal is adjusted, determine that thesending state of the reference signal of the cell needs to be adjusted.

Preferably, the processor 91 is specifically configured to:

when one or more of the following cases occur in the cell, determinethat the sending state of the reference signal needs to be adjusted:

a radio resource is overloaded;

a backhaul link network is overloaded;

a transmission delay in a backhaul link exceeds a set threshold; or

a hardware resource is overloaded.

Preferably, the transmitter 92 is further configured to:

after the processor 91 adjusts the sending state of the reference signalof the cell, send indication information to a communications device inthe cell, where the indication information is used for indicating atleast one of the following indications:

an indication that the communications device in the cell determines,according to the adjusted sending state, of the reference signal,indicated by the indication information, whether to measure thereference signal;

an indication that the communications device in the cell measures thereference signal according to adjusted measurement configurationinformation indicated by the indication information;

an indication that the communications device in the cell no longermeasures the reference signal; or

an indication that the communications device in the cell measures a settype of reference signals, where the set type is different from a typeof the adjusted reference signal.

Preferably, the transmitter 92 is specifically configured to send theindication information according to at least one of the following:

broadcasting the indication information to the communications device inthe cell by using a system information block SIB; sending the indicationinformation to the communications device in the cell by using dedicatedradio resource control RRC signaling; broadcasting the indicationinformation to the communications device in the cell by using a physicallayer broadcast message; or sending the indication information to thecommunications device in the cell by using downlink control informationDCI.

Preferably, the transmitter 92 is further configured to:

after the processor 91 adjusts the sending state of the reference signalof the cell, notify the communications device in the cell to receivedata and/or control signaling on a resource carrying the referencesignal.

Preferably, the transmitter 92 is specifically configured to notify,according to at least one of the following manners, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal:

notifying, by using a system information block SIB, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal;

notifying, by using dedicated radio resource control RRC signaling, thecommunications device in the cell to receive the data and/or controlsignaling on the resource carrying the reference signal;

notifying, by using a physical layer broadcast message, thecommunications device in the cell to receive the data and/or controlsignaling on the resource carrying the reference signal; or

notifying, by using downlink control information DCI, the communicationsdevice in the cell to receive the data and/or control signaling on theresource carrying the reference signal.

Preferably, the transmitter 92 is specifically configured to:

after the communications device in the cell is notified to receive thecontrol signaling on the resource carrying the reference signal, send,by using a physical layer control channel, the control signaling on theresource carrying the reference signal to the communications device inthe cell; and/or

after the communications device in the cell is notified to receive thedata on the resource occupied when the reference signal is carried,send, by using a physical layer data channel, the data on the resourcecarrying the reference signal to the communications device in the cell.

Preferably, the transmitter 92 is further configured to: after theprocessor 91 adjusts the sending state of the reference signal of thecell,

notify a communications node of a neighboring cell of the adjustedsending state of the reference signal of the cell, to enable thecommunications node of the neighboring cell to determine, according tothe adjusted sending state of the reference signal of the cell, whetherUE in the neighboring cell needs to measure the cell, and/or, determineconfiguration information for measuring the cell by UE in theneighboring cell.

Preferably, the transmitter 92 is further configured to: after theprocessor 91 adjusts the sending state of the reference signal of thecell that belongs to the first communications node, send the referencesignal including load information of the cell.

Preferably, the transmitter 92 is specifically configured to:

send the reference signal according to a reference signal sending periodcorresponding to the load information;

send the reference signal including encoding information correspondingto the load information; or

send the reference signal by using a bandwidth corresponding to the loadinformation.

Preferably, the processor 91 is specifically configured to:

adjust the sending state of the reference signal of the cell by using acommunications device managed by the first communications node; or

adjust the sending state of the reference signal according to anadjustment manner indicated by a radio resource control RRC layer of thefirst communications node.

Preferably, the processor 91 is further configured to:

after it is determined that the sending state of the reference signalneeds to be restored, restore the sending state of the reference signal;and the transmitter 92 is further configured to: send the referencesignal by using a restored sending state.

Preferably, the reference signal is at least one of the following typesof reference signals:

a synchronization signal;

a discovery reference signal Discovery RS;

a channel state information reference signal CSI-RS;

a cell-specific reference signal CRS;

a common demodulation reference signal DM-RS; or

a cell-common reference signal.

FIG. 10 is a structural diagram of a communications device forperforming signal transmission according to Embodiment 8 of the presentinvention, where the communications device includes:

a receiver 101, configured to receive an adjusted reference signal, of acell in which the communications device is located, sent by a firstcommunications node, and transmit the adjusted reference signal to aprocessor 102; and

the processor 102, configured to receive the adjusted reference signal,of the cell, transmitted by the receiver 101, and perform communicationaccording to the adjusted reference signal, where

the reference signal is: the reference signal sent by the firstcommunications node according to an adjusted sending state of thereference signal.

Preferably, the processor 102 is further configured to:

receive indication information sent by the first communications node,where the indication information is used for indicating the sendingstate, of the reference signal, adjusted by the first communicationsnode; and adjust measurement of the reference signal according to theadjusted sending state of the reference signal.

Preferably, the processor 102 is specifically configured to:

determine, according to the adjusted sending state, of the referencesignal, indicated by the indication information, whether to measure thereference signal;

measure the reference signal according to adjusted measurementconfiguration information indicated by the indication information;

no longer measure the reference signal according to an indication, of nolonger measuring the reference signal, in the indication information; or

measure a first type of reference signals according to an indication, ofmeasuring the first type of reference signals, in the indicationinformation, where the first type is different from a type of theadjusted reference signal.

Preferably, the receiver 101 is specifically configured to:

receive, by using a system information block SIB, the indicationinformation sent by a communications node of the cell in which thecommunications device is located; receive, by using dedicated radioresource control RRC signaling, the indication information sent by acommunications node of the cell in which the communications device islocated; receive, by using a physical layer broadcast message, theindication information sent by a communications node of the cell inwhich the communications device is located; or receive, by usingdownlink control information DCI, the indication information sent by acommunications node of the cell in which the communications device islocated.

FIG. 11 is a structural diagram of a communications device forperforming signal transmission according to Embodiment 9 of the presentinvention, where the communications device includes:

a receiver 111, configured to receive notification information sent by afirst communications node, and transmit the received notificationinformation to a processor 112, where the notification information issent by the first communications node after the first communicationsnode adjusts a sending state of a reference signal of a cell in whichthe communications device is located; and after an indication, ofreceiving data and/or control signaling on a resource carrying thereference signal, indicated by the processor 112 is received, receive,according to the notification information, the data and/or controlsignaling on the resource carrying the reference signal; and

the processor 112, configured to receive the notification informationtransmitted by the receiver 111, and instruct, according to thenotification information, the receiver 111 to receive the data and/orcontrol signaling on the resource carrying the reference signal.

Preferably, the receiver 111 is specifically configured to:

receive, by using a physical layer control channel, the controlsignaling on the resource carrying the reference signal; and/or,receive, by using a physical layer data channel, the data on theresource carrying the reference signal.

Preferably, the receiver 111 is specifically configured to: receive, inat least one of the following manners, the notification information sentby the first communications node:

receiving, by using a system information block SIB, the notificationinformation sent by the first communications node; receiving, by usingdedicated radio resource control RRC signaling, the notificationinformation sent by the first communications node; receiving, by using aphysical layer broadcast message, the notification information sent bythe first communications node; or receiving, by using downlink controlinformation DCI, the notification information sent by the firstcommunications node.

FIG. 12 is a structural diagram of a signal transmission deviceaccording to Embodiment 10 of the present invention, where the signaltransmission device includes:

a receiver 121, configured to receive an adjusted sending state, of areference signal of a neighboring cell, sent by a communications node ofthe neighboring cell, and transmit the received adjusted sending stateof the reference signal of the neighboring cell to a processor 122; and

the processor 122, configured to control, according to the adjustedsending state, of the reference signal of the neighboring cell, receivedby the receiver 121, measurement of a cell of user equipment UE servedby the device.

Preferably, the processor 122 is specifically configured to:

determine, according to the adjusted sending state, of the referencesignal of the neighboring cell, received by the receiver 121, whetherthe UE served by the device needs to measure the neighboring cell,and/or, determine configuration information for measuring theneighboring cell by the UE served by the device.

FIG. 13 is a structural diagram of a signal transmission deviceaccording to Embodiment 11 of the present invention, where the signaltransmission device includes:

a processor 131, configured to generate a reference signal of a cell inwhich a first communications node is located, and transmit the generatedreference signal to a transmitter 132, where the reference signalcarries load information of the cell in which the first communicationsnode is located; and

the transmitter 132, configured to receive the reference signalgenerated by the processor 131, and send the reference signal, where thereference signal is used for enabling a communications device thatdetects the reference signal to determine, according to the loadinformation, whether to measure the cell, or determine whether to reporta measurement result of measuring the cell, or determine whether toaccess the cell.

Preferably, the transmitter 132 is specifically configured to: send thereference signal according to at least one of the following:

sending the reference signal according to a reference signal sendingperiod corresponding to the load information;

sending the reference signal including encoding informationcorresponding to the load information; or

sending the reference signal by using a bandwidth corresponding to theload information.

FIG. 14 is a structural diagram of a communications device forperforming signal transmission according to Embodiment 12 of the presentinvention, where the communications device includes:

a receiver 141, configured to receive a reference signal sent by a firstcommunications node, where the reference signal carries load informationof a cell in which the first communications node is located, andtransmit the received reference signal to a processor 142; and

the processor 142, configured to receive the reference signaltransmitted by the receiver 141, and determine, according to the loadinformation, whether to measure the cell, or determine whether to reporta measurement result of measuring the cell, or determine whether toaccess the cell.

Preferably, the processor 142 is specifically configured to determinethe load information according to at least one of the following:

determining, according to a reference signal sending period of sendingthe reference signal by the first communications node, the loadinformation included in the reference signal;

determining the load information according to encoding informationincluded in the reference signal; or

determining the load information according to a bandwidth occupied whenthe first communications node sends the reference signal.

On the basis of a same inventive concept, an embodiment of the presentinvention further provides a signal transmission method corresponding tothe signal transmission device. Reference may be made to implementationof the following method for specific implementation of the foregoingdevice.

FIG. 15 is a flowchart of a signal transmission method according toEmbodiment 1 of the present invention, where the signal transmissionmethod includes:

S151: A first communications node adjusts a sending state of a referencesignal of a cell that belongs to the first communications node.

S152: The first communications node sends the reference signal of thecell according to an adjusted sending state of the reference signal.

Herein, an adjusted reference signal refers to a reference signal thatcan enable UE, a base station or the like of another cell to discover acell (referred to as a target cell below) of the first communicationsnode, where the reference signal may include a cell identity (Identity,ID). The first communications node may be any device that can form ormanage a particular signal coverage area, for example, a base station, abase station processor, and user equipment (User Equipment, UE).Specifically, the first communications node may be a base station,managing the target cell, in an LTE system. Correspondingly, anotherdevice may be specifically, for example, user equipment (User Equipment,UE) and/or a base station, outside the target cell. The firstcommunications node may further be an RNC in a WCDMA system.Correspondingly, the another device may be specifically, for example,UE, a Node B or an RNC, outside the target cell. The firstcommunications node may further be UE in Device-to-Device (D2D)communication. The target cell may be a signal coverage area formed bythe UE. The another device may be specifically, for example, UE, a basestation or a base station processor, outside the target cell.

In specific implementation, when the first communications nodedetermines that the sending state of the reference signal needs to beadjusted, to prevent the another device from detecting or measuring oraccessing the target cell, or to reduce a probability that the anotherdevice detects or measures or accesses the target cell, the firstcommunications node adjusts the sending state of the reference signal ofthe target cell. Specifically, when determining that the managed targetcell is overloaded, the first communications node may adjust the sendingstate of the reference signal.

This embodiment of the present invention may be applied to cellhandover, where the first communications node actively chooses whetherto allow another UE to access the target cell, or may also be applied tocoordinated multiple point (Coordinated multiple point, CoMP)transmission, where the first communications node actively chooseswhether to participate in CoMP transmission of another communicationsnode, or may also be applied to assisted transmission of backhaulnetwork data between base stations, or may further be applied todevice-to-device (Device-to-Device, D2D) communication between UEs, orthe like.

When this embodiment of the present invention is applied to cellhandover, before UE detects or measures a target cell or accesses atarget cell, the UE can know, according to a current sending state of areference signal of the target cell, whether the target cell may acceptthe UE, thereby avoiding unnecessary workload produced because thetarget cell refuses to accept the UE. When this embodiment of thepresent invention is applied to CoMP transmission, before a base stationrequests another base station for coordinated transmission, the basestation may know whether the another base station currently has acapability of CoMP transmission, thereby avoiding unnecessary signalinginteractions between the base station and the another base station.

FIG. 16 is a schematic diagram of assisted transmission of backhaulnetwork data between base stations according to an embodiment of thepresent invention. When a backhaul network resource of a base station 1is insufficient or unavailable, the base station 1 may be connected to acore network by using an air interface between the base station 1 and abase station 2. Specifically, the base station 1 transmits uplink(Uplink, UL) data to the base station 2, and the base station 2transmits, by using a backhaul network resource of the base station 2,the received data of the base station 1 to the core network; or, thecore network transmits downlink (Downlink, DL) data to the base station2, and the base station 2 transmits, by using the air interface betweenthe base station 1 and the base station 2, the received data to the basestation 1. A precondition for application of such a transmission methodis that the base station 2 can provide such a capability of assistingtransmission of backhaul network data; for example, when the basestation 2 has over load (over load), the base station 2 may be unable toprovide the capability, and when the base station 2 has low load (lowload), the base station 2 can provide the capability. In this embodimentof the present invention, before the base station 1 determines totransmit data in such a transmission manner, the base station 1 canknow, according to a sending state, of a reference signal, sent by thebase station 2, whether the base station 2 currently can provide thecapability of assisting transmission of backhaul network data, so as toavoid occurrence of a case that when the base station 1 sends a bearerrequest to the base station 2, that is, requests the base station 2 toassist transmission of backhaul network data, the base station 2 rejectsthe request of the base station 1 because the base station 2 cannotprovide the capability of assisting transmission of backhaul networkdata. Therefore, by means of this embodiment of the present invention,unnecessary signaling interactions between base stations can be reduced.

When this embodiment of the present invention is applied to D2Dcommunication, before UE determines to transmit data with anothercommunications device in a D2D communication manner, the UE can know,according to a sending state of a reference signal sent by the anothercommunications device, whether the another communications devicecurrently has a capability of performing D2D communication with the UE,thereby avoiding unnecessary signaling interactions produced because ofa rejection when the UE sends a D2D communication request to the anothercommunications device.

Preferably, in step S151, the adjusting, by a first communications node,a sending state of a reference signal of a cell that belongs to thefirst communications node includes: adjusting, by the firstcommunications node, the sending state of the reference signal to bestopping sending the reference signal of the cell; and the sending, bythe first communications node, the reference signal of the cellaccording to an adjusted sending state of the reference signal includes:stopping, by the first communications node, sending the reference signalof the cell; or

the adjusting, by a first communications node, a sending state of areference signal of a cell that belongs to the first communications nodeincludes: lowering, by the first communications node, a sending power ofsending the reference signal of the cell; and the sending, by the firstcommunications node, the reference signal of the cell according to anadjusted sending state of the reference signal includes: sending, by thefirst communications node, the reference signal by using the loweredsending power; or

the adjusting, by a first communications node, a sending state of areference signal of a cell that belongs to the first communications nodeincludes: extending, by the first communications node, a sending periodof sending the reference signal of the cell; and the sending, by thefirst communications node, the reference signal of the cell according toan adjusted sending state of the reference signal includes: sending, bythe first communications node, the reference signal by using theextended sending period; or

the adjusting, by a first communications node, a sending state of areference signal of a cell that belongs to the first communications nodeincludes: lowering, by the first communications node, a bandwidthoccupied when the reference signal of the cell is sent; and the sending,by the first communications node, the reference signal of the cellaccording to an adjusted sending state of the reference signal includes:sending, by the first communications node, the reference signal by usingthe lowered bandwidth.

In a specific implementation process, if the first communications nodedetermines that the first communications node needs to prevent anotherdevice, for example, UE of another cell, from detecting or measuring oraccessing a target cell, the first communications node may stop sendingthe reference signal; if the first communications node determines thatthe first communications node only needs to reduce a probability thatthe another device detects or measures or accesses the target cell, thefirst communications node may, instead of stopping sending the referencesignal, only increase difficulty of detecting the target cell by theanother device in a manner of lowering a sending power, extending asending period, lowering an occupied bandwidth, or the like.Specifically, a coverage area of the reference signal can be lowered bylowering the sending power of sending the reference signal, so that aquantity of devices that detect or measure or access the target cell isreduced. The probability that the another device detects or measures oraccesses the target cell can be reduced by extending the sending periodof sending the reference signal. The coverage area of the referencesignal can also be lowered by sending the reference signal by using alowered occupied bandwidth. There are specifically two forms of loweringthe occupied bandwidth: In one manner, a total bandwidth is lowered; forexample, previously a 20M bandwidth is occupied to send the referencesignal, and after adjustment, only a 10M bandwidth is occupied to sendthe reference signal; or, previously 110 physical resource blocks(Physical Resource Block, PRB) are occupied to send the referencesignal, and after adjustment, only 6 PRBs in the middle are occupied tosend the reference signal. In another manner, a total bandwidth is keptunchanged, but a density of frequency resources included in the totalbandwidth is reduced; for example, a frequency density may be adjustedto be half as it is before.

Preferably, before step S151, the method further includes:

determining, by the first communications node, that the sending state ofthe reference signal of the cell needs to be adjusted.

In specific implementation, when determining that the firstcommunications node needs to prevent another device from detecting ormeasuring or accessing the target cell, or reduce the probability thatthe another device detects or measures or accesses the target cell, thefirst communications node may determine to adjust the sending state ofthe reference signal of the target cell. Specifically, when determiningthat the managed target cell is overloaded, the first communicationsnode may adjust the sending state of the reference signal.

Preferably, the determining, by the first communications node, that thesending state of the reference signal of the cell needs to be adjustedincludes:

when one or more of the following cases occur in the cell, determining,by the first communications node, that the sending state of thereference signal needs to be adjusted:

a radio resource is overloaded;

a backhaul link network is overloaded;

a transmission delay in a backhaul link exceeds a set threshold; or

a hardware resource is overloaded.

In a specific implementation process, when determining that the targetcell is overloaded, the first communications node may adjust the sendingstate of the reference signal. There are multiple manifestations of thatthe target cell is overloaded, and the manifestations may bespecifically: a radio resource is overloaded, a TNL network isoverloaded, a hardware resource is overloaded, or the like. For a radioresource, a physical resource block (Physical Resource Block, PRB) isgenerally used as a minimum scheduling unit. In specific implementation,the first communications node may determine that a radio resource isoverloaded when an occupation ratio of a radio resource exceeds a setthreshold. For example, when a current occupation ratio of PRBs exceeds70%, the first communications node determines that a radio resource isoverloaded. A scheduler of the target cell may specifically determinethat a radio resource is overloaded. When a TNL network is overloaded,it refers to that if the first communications node receives a linkcongestion indication fed back by another communications node when thefirst communications node sends data to the another communications node,for example, a routing device, it is determined that currently abackhaul link network is overloaded. A hardware resource is overloaded;for example, currently usage of a central processing unit (CentralProcessing Unit, CPU) exceeds a set threshold, or an occupation ratio ofmemory exceeds a set threshold.

In this embodiment of the present invention, after the sending state ofthe reference signal is adjusted, the target cell continues tocommunicate with a communications device that has gained access, forexample, UE or a base station; that is, after the sending state of thereference signal is adjusted, the target cell continues to keeptransmission states of a control channel and a data channel.

Preferably, after step S151, the method further includes:

sending, by the first communications node, indication information to acommunications device in the cell, where

the indication information is used for indicating at least one of thefollowing indications:

an indication that the communications device in the cell determines,according to the adjusted sending state, of the reference signal,indicated by the indication information, whether to measure thereference signal;

an indication that the communications device in the cell measures thereference signal according to adjusted measurement configurationinformation indicated by the indication information;

an indication that the communications device in the cell no longermeasures the reference signal; or

an indication that the communications device in the cell measures a settype of reference signals, where the set type is different from a typeof the adjusted reference signal.

Herein, the communications device may be a wireless communicationsdevice such as UE or a base station. In a specific implementationprocess, the first communications node may stop sending the referencesignal to prevent another device from detecting, measuring, or accessingthe target cell, or reduce, in a manner of lowering a sending power,extending a sending period, lowering an occupied bandwidth, or the like,the probability that the another device detects or measures or accessesthe target cell. After adjusting the sending state of the referencesignal, the first communications node may send the indicationinformation to the communications device in the target cell. That is,after adjusting the sending state of the reference signal, the firstcommunications node determines how to enable the communications devicein the target cell to continue with RRM measurement, channel stateinformation (Channel State Information, CSI) measurement, radio linkmanagement (Radio Link Management, RLM) measurement, and the like. Inspecific implementation, a manner of indication by the indicationinformation may be explicit indication, or may also be implicitindication. That is, the first communications node may have a task,which needs to be executed by the communications device, representedexplicitly in the indication information, or may also have a task, whichneeds to be executed by the communications device, manifested in otherinformation related to the specifically indicated task, and thecommunications device may determine, according to an agreement with anetwork side, the indication information from the other informationrelated to the specifically indicated task.

Specifically, the indication information may include the adjustedsending state of the reference signal, and the communications device maydetermine, according to the adjusted sending state, of the referencesignal, indicated by the indication information, whether to measure thereference signal whose sending state is adjusted. For example, if theadjusted sending state of the reference signal is stopping sending thereference signal, the communications device determines that thecommunications device no longer measures the reference signal whosesending state is adjusted. If the adjusted sending state of thereference signal includes that sending is not stopped, thecommunications device determines to measure the reference signal whosesending state is adjusted. The indication information may explicitlyindicate that the communications device determines whether to measurethe adjusted sending state of the reference signal, or it may also bethat after receiving the reference signal whose sending state isadjusted, the communications device determines, according to anagreement with a network side, whether to measure the reference signalwhose sending state is adjusted. The indication information may furtherinclude adjusted measurement configuration information, and thecommunications device measures, according to the measurementconfiguration information, the reference signal whose sending state isadjusted. The adjusted measurement configuration information may be, ascompared with the measurement configuration information beforeadjustment, the measurement configuration information in which ameasurement period is extended and/or the measurement configurationinformation in which a bandwidth occupied by measurement is lowered.Specifically, the indication information may explicitly indicate thatthe communications device measures, according to the measurementconfiguration information, the reference signal whose sending state isadjusted, or it may also be that after receiving the measurementconfiguration information, according to the agreement with the networkside, the communications device measures, according to the measurementconfiguration information, the reference signal whose sending state isadjusted. The indication information may further indicate that thecommunications device no longer measures the reference signal whosesending state is adjusted. In this case, after the communications deviceno longer measures, according to the indication information, thereference signal whose sending state is adjusted, the communicationsdevice may select another reference signal to perform measurement.Herein, the another reference signal may be agreed upon in advancebetween the communications device and the network side, or may also bedecided by the communications device. The indication information mayfurther indicate that the communications device measures a set type ofreference signals. For example, if the adjusted sending state of thereference signal is stopping sending, the first communications node mayfurther indicate that the communications device of the target cellperforms RRM measurement, CSI measurement, RLM measurement, and the likeby using another reference signal.

Preferably, the sending, by the first communications node, indicationinformation to a communications device in the cell includes at least oneof the following:

broadcasting, by the first communications node, the indicationinformation to the communications device in the cell by using a systeminformation block (System Information Block, SIB); sending theindication information to the communications device in the cell by usingdedicated radio resource control RRC signaling; broadcasting theindication information to the communications device in the cell by usinga physical layer broadcast message; or sending the indicationinformation to the communications device in the cell by using downlinkcontrol information (Downlink Control Information, DCI).

Preferably, after step S151, the method further includes:

notifying, by the first communications node, the communications devicein the cell to receive data and/or control signaling on a resourcecarrying the reference signal.

In a specific implementation process, after the first communicationsnode stops sending reference signals that need to be adjusted, resourcesoccupied before sending of these reference signals is stopped are usedto transmit data and/or control signaling between the firstcommunications node and all communications devices or a setcommunications device in the target cell. If the first communicationsnode does not stop sending the reference signals that need to beadjusted, and instead, only extends a sending period or lowers anoccupied bandwidth, or the like to send the reference signals, the firstcommunications node may notify the communications device in the targetcell to receive data and/or control signaling on some of the resourcesthat carry the reference signals before. Herein, the communicationsdevice may be a wireless communications device such as UE or a basestation. Specifically, the first communications node may explicitlynotify, or may also implicitly notify the communications device in thetarget cell to receive data and/or control signaling on some of theresources that carry the reference signals before. For example, if thefirst communications node adjusts a reference signal sending period from100 ms to 300 ms, idle 200 ms after the sending period is adjusted maybe used to send data and/or control signaling to the communicationsdevice in the target cell. The first communications node may explicitlynotify the communications device in the target cell to receive dataand/or control signaling in the idle 200 ms, or according to anagreement with a network side, the communications device may alsodetermine, according to the adjusted sending period of the referencesignal of the first communications node, that the communications deviceneeds to receive data and/or control signaling within the idle time. Foranother example, if the first communications node adjusts a 20Mbandwidth occupied to send the reference signal to only an occupied 1.4Mbandwidth in the middle, after the bandwidth occupied to send thereference signal is adjusted, the first communications node mayexplicitly or implicitly notify the communications device in the targetcell that an idle bandwidth is used to send data and/or controlsignaling to the communications device in the target cell; that is,after adjusting the sending state of the reference signal, the firstcommunications node may configure, for the communications device, a timeslot and/or frequency resource, used to transmit data and/or controlsignaling, in resources that carry the reference signal before.

Preferably, the first communications node notifies, according to atleast one of the following manners, the communications device in thecell to receive the data and/or control signaling on the resourcecarrying the reference signal:

notifying, by the first communications node by using a systeminformation block SIB, the communications device in the cell to receivethe data and/or control signaling on the resource carrying the referencesignal;

notifying, by the first communications node by using dedicated radioresource control RRC signaling, the communications device in the cell toreceive the data and/or control signaling on the resource carrying thereference signal;

notifying, by the first communications node by using a physical layerbroadcast message, the communications device in the cell to receive thedata and/or control signaling on the resource carrying the referencesignal; or

notifying, by the first communications node by using downlink controlinformation DCI, the communications device in the cell to receive thedata and/or control signaling on the resource carrying the referencesignal.

Preferably, after the first communications node notifies thecommunications device in the cell to receive the control signaling onthe resource carrying the reference signal, the first communicationsnode sends, by using a physical layer control channel, the controlsignaling on the resource carrying the reference signal to thecommunications device in the cell; and/or

after the first communications node notifies the communications devicein the cell to receive the data on the resource occupied when thereference signal is carried, the first communications node sends, byusing a physical layer data channel, the data on the resource carryingthe reference signal to the communications device in the cell.

In a specific implementation process, the physical layer control channelmay be specifically a physical downlink control channel (PhysicalDownlink Control Channel, PDCCH), an enhanced physical downlink controlchannel (Enhanced Physical Downlink Control Channel, ePDCCH), a physicalHARQ indicator channel (Physical Hybrid ARQ Indicator Channel, PHICH) orthe like; the physical layer data channel may be specifically a physicalmulticast channel (Physical Multicast Channel, PMCH), a physicaldownlink shared channel (Physical Downlink Shared Channel, PDSCH) or thelike.

Preferably, after step S151, the method further includes:

notifying, by the first communications node, a communications node of aneighboring cell of the adjusted sending state of the reference signalof the cell, to enable the communications node of the neighboring cellto determine, according to the adjusted sending state of the referencesignal of the cell, whether UE in the neighboring cell needs to measurethe cell, and/or, determine configuration information for measuring thecell by UE in the neighboring cell.

In a specific implementation process, herein, the first communicationsnode and the communications node may be specifically a base station or abase station processor. After adjusting the sending state of thereference signal of the target cell, the first communications node mayfurther send the adjusted sending state of the reference signal to thecommunications node of the neighboring cell, to enable thecommunications node of the neighboring cell to determine, according tothe adjusted sending state of the reference signal, whether UE in theneighboring cell needs to measure the target cell. For example, if theadjusted sending state of the reference signal of the firstcommunications node is stopping sending the reference signal, thecommunications node of the neighboring cell determines that there is noneed to measure the target cell. If the adjusted sending state of thereference signal of the first communications node is lowering a sendingpower for sending and/or extending a sending period for sending and/orlowering an occupied bandwidth for sending or the like, thecommunications node of the neighboring cell may determine that the UEstill needs to measure the target cell, but the measurementconfiguration information needs to be adjusted. If the firstcommunications node extends the sending period to send the referencesignal, the communications node of the neighboring cell adjusts,according to the sending state of the reference signal, a measurementperiod of the UE in the current cell, to enable the UE to shorten aperiod of measuring the target cell. For example, the firstcommunications node adjusts the sending state of the reference signal,and one time of sending in every 5 subframes is adjusted to one time ofsending in every 10 subframes. Therefore, the communications node of theneighboring cell adjusts the measurement period of measuring the targetcell by the UE in the current cell, so that measuring the target cell bythe UE in the current cell once in every 5 subframes is adjusted tomeasuring the target cell once in every 10 subframes. Correspondingly,if the first communications node lowers an occupied bandwidth to sendthe reference signal, the communications node of the neighboring celllowers a bandwidth occupied when the UE in the current cell measures thetarget cell. If the first communications node lowers a sending power tosend the reference signal, when determining that signal transmission hasa path loss, the communications node of the neighboring cell uses anadjusted sending power as a transmission power of the target cell, andcompares the adjusted sending power with an actual received power, todetermine the path loss, so as to determine a geographical relationshipbetween the target cell and the neighboring cell.

Preferably, after the adjusting, by a first communications node, asending state of a reference signal of a cell that belongs to the firstcommunications node, the method further includes:

after the first communications node determines that the reference signalneeds to be sent, sending the reference signal including loadinformation of the cell.

Herein, a communications device that detects the reference signal may bespecifically a base station, UE or the like. By means of this embodimentof the present invention, the communications device does not need toread a system broadcast message of an RRC layer, and also does not needto read other additional physical channel information, and thecommunications device can acquire load information of a target cell atthe same time when the target cell is detected. Such a manner ofobtaining the load information is highly efficient, and thecommunications device may determine, according to the load information,whether to measure the target cell, or determine whether to report ameasurement result of measuring the target cell, or determine whether toaccess the target cell. For example, the load information indicates thatthe target cell has over load, and the communications device maydetermine not to measure the target cell, or not to report themeasurement result, or not to access the target cell. The loadinformation indicates that the target cell has light load, and thecommunications device may determine to measure the target cell, or toreport the measurement result, or to access the target cell. Thecommunications device may implement, according to configuration of thereference signal, fast detection of the reference signal andsimultaneous acquisition of load of the target cell, thereby avoiding areduced throughput because a serving cell cannot perform scheduling forthe communications device due to long time reading of a system broadcastmessage.

Preferably, the sending, by the first communications node, the referencesignal including load information of the cell includes at least one ofthe following:

sending, by the first communications node, the reference signalaccording to a reference signal sending period corresponding to the loadinformation;

sending, by the first communications node, the reference signalincluding encoding information corresponding to the load information; or

sending, by the first communications node, the reference signal by usinga bandwidth corresponding to the load information.

In a specific implementation process, the load information may be addedto the reference signal in various manners. For example, the firstcommunications node sends the reference signal by using the referencesignal sending period corresponding to the load information. Accordingto an agreement with a network side, the communications device maydetermine the load information of the target cell according to thereference signal sending period. For example, there may be three loadconditions of a cell, which are separately, in an ascending order ofload, low load (low load), high load (high load), and over load (overload). For a cell with low load, the reference signal sending period isset to 100 ms; for a cell with high load, the reference signal sendingperiod is set to 200 ms; and for a cell with over load, the referencesignal sending period is set to 300 ms. Correspondingly, the firstcommunications node sends the reference signal by occupying thebandwidth corresponding to the load information, and the communicationsdevice determines a load condition of the target cell according to thebandwidth occupied by the reference signal. The encoding informationcorresponding to the load information may be further added to thereference signal. For example, one bit is added to the reference signalto represent the load information. Specifically, bit 0 represents normalload of a cell, and bit 1 represents over load of a cell.

Preferably, in step S151, the adjusting, by a first communications node,a sending state of a reference signal of a cell that belongs to thefirst communications node includes:

adjusting, by the first communications node, the sending state of thereference signal of the cell by using the communications device managedby the first communications node; or

adjusting, by a physical layer of the first communications node, thesending state of the reference signal according to an adjustment mannerindicated by a radio resource control (Radio Resource Control, RRC)layer of the first communications node.

In a specific implementation process, in a process of sending thereference signal, the first communications node may determine, by usinga radio resource management (Radio Resource Management, RRM) function ofthe first communications node, that the sending state of the referencesignal needs to be adjusted, and may then adjust the sending state ofthe reference signal, or may also instruct another managedcommunications node in the target cell to adjust the sending state ofthe reference signal. Specifically, the first communications node may bea base station, and the target cell is a signal coverage area formed bysignal transmission of the base station; in this case, the base stationmay adjust the sending state of the reference signal. When the firstcommunications node instructs another managed communications node toadjust the sending state of the reference signal, the firstcommunications node may be a base station, and the managed anothercommunications node may be a remote radio port (Remote Radio Head, RRH)or the like.

In a specific implementation process, the RRC layer of the firstcommunications node may determine a specific adjustment manner ofadjusting the sending state of the reference signal, for example,stopping sending the reference signal, lowering a sending power to sendthe reference signal, lowering an occupied bandwidth to send thereference signal, extending a sending period to send the referencesignal, and transmit the determined adjustment manner to a physicallayer, to instruct the physical layer to adjust, according to theadjustment manner, the sending state of the reference signal.

Preferably, after step S151, the method further includes:

after the first communications node determines that the sending state ofthe reference signal needs to be restored, restoring the sending stateof the reference signal, and sending the reference signal by using arestored sending state.

In a specific implementation process, after load of the target cellbecomes normal, the first communications node may restore the sendingstate of the reference signal. For example, if sending of the referencesignal is stopped before, sending of the reference signal is restored.If the sending power of sending the reference signal is lowered before,the previous sending power is restored to send the reference signal. Ifthe sending period of sending the reference signal is extended before,the previous sending period is restored to send the reference signal. Ifthe bandwidth occupied to send the reference signal is lowered before,the previous occupied bandwidth is restored to send the referencesignal.

In a specific implementation process, an operation related torestoration of the sending state of the reference signal corresponds toprevious adjustment of the sending state of the reference signal; forexample:

Preferably, the restoring, by the first communications node, the sendingstate of the reference signal of the target cell includes: restoring, bythe first communications node, the sending state of the reference signalof the target cell by using another communications node managed by thefirst communications node.

Preferably, the restoring, by the first communications node, the sendingstate of the reference signal of the target cell includes: restoring, bya physical layer of the first communications node, the sending state ofthe reference signal according to a restoration manner indicated by theRRC layer of the first communications node.

Preferably, after the restoring, by the first communications node, thesending state of the reference signal, the method further includes:sending, by the first communications node, indication information to thecommunications device in the target cell, where the indicationinformation is used for instructing the communications device in thetarget cell to determine, according to the restored sending state of thereference signal indicated by the indication information, whether tomeasure the reference signal after the sending state is restored; or,the indication information is used for instructing the communicationsdevice in the target cell to measure, according to restored measurementconfiguration information indicated by the indication information, thereference signal after the sending state is restored; or, the indicationinformation is used for instructing the communications device in thetarget cell to restore measurement of the reference signal.

Preferably, after the restoring, by the first communications node, thesending state of the reference signal of the target cell, the methodfurther includes: notifying, by the first communications node, thecommunications device in the target cell of that sending of thereference signal is restored in the target cell.

Preferably, the first communications node may notify, by using an SIB,dedicated RRC signaling, a physical layer broadcast message, DCI or thelike, the communications device in the target cell of that sending ofthe reference signal is restored in the target cell.

Preferably, after the restoring, by the first communications node, thesending state of the reference signal of the target cell, acommunications node of a neighboring cell may further be notified ofthat the sending state of the reference signal has been restored in thetarget cell, to enable the communications node of the neighboring cellto determine, according to the restored sending state of the referencesignal of the target cell, whether UE in the neighboring cell needs tomeasure the target cell, or, determine configuration information formeasuring the target cell by UE in the neighboring cell.

Preferably, the first communications node may further receive therestored sending state, of the reference signal of the neighboring cell,sent by a communications node of the neighboring cell. The firstcommunications node determines, according to the received restoredsending state of the reference signal of the neighboring cell, whetherUE in the target cell needs to measure the neighboring cell, or,determines configuration information for measuring the neighboring cellby UE in the target cell.

Preferably, the foregoing reference signal is a cell-common referencesignal. That is, herein, the reference signal is a cell-level referencesignal, and all communications devices that have gained access to thecell can measure the reference signal.

Preferably, the foregoing reference signal is at least one of thefollowing types of reference signals:

a synchronization signal;

a discovery reference signal (Discovery Reference Signal, Discovery RS);

a channel state information reference signal (Channel State InformationReference Signals, CSI-RS);

a cell-specific reference signal (Cell-specific Reference Signal, CRS);or

a common demodulation reference signal (Demodulation Reference Signals,DM-RS).

It should be noted that, herein, the Discovery RS may also be referredto as a detection reference signal (Detection Reference Signal,Detection RS). The communications device may measure the referencesignal by using a physical downlink shared channel (Physical DownlinkShared Channel, PDSCH). Herein, the common DM-RS is a cell-leveldemodulation reference signal, and may be represented by using a commonsequence or a sequence of a cell. That is, the common DM-RS is ademodulation reference signal that can be measured by all communicationsdevices in a cell. The synchronization signal includes a primarysynchronization signal (Primary Synchronization Signal, PSS) and asecondary synchronization signal (Secondary Synchronization Signal,SSS).

Preferably, the method further includes:

receiving, by the first communications node, the adjusted sending state,of the reference signal of the neighboring cell, sent by acommunications node of the neighboring cell; and

determining, by the first communications node according to the receivedadjusted sending state of the reference signal of the neighboring cell,whether UE in the target cell needs to measure the neighboring cell, or,after it is determined that the UE in the target cell needs to measurethe neighboring cell, determining configuration information formeasuring the neighboring cell by the UE in the target cell.

In a specific implementation process, the first communications node maybe both a sender of a reference signal of a current cell and a receiverof a reference signal of a neighboring cell, and may determine,according to a received adjusted sending state of a the reference signalof the neighboring cell, whether UE in a target cell needs to measurethe neighboring cell, or after it is determined that the UE in thetarget cell needs to measure the neighboring cell, adjust measurementconfiguration information for the UE in the target cell. For a specificstep of adjusting the measurement configuration information, referencemay be made to the foregoing description of that the communications nodeof the neighboring cell adjusts the measurement configurationinformation of the UE in the neighboring cell.

FIG. 17 is a flowchart of a signal transmission method according toEmbodiment 2 of the present invention, where the signal transmissionmethod includes:

S171: A communications device receives an adjusted reference signal, ofa cell in which the communications device is located, sent by a firstcommunications node.

S172: The communications device performs communication according to theadjusted reference signal.

The reference signal is: the reference signal sent by the firstcommunications node according to an adjusted sending state of thereference signal.

Preferably, before step S171, the method further includes:

receiving, by the communications device, indication information sent bythe first communications node, where the indication information is usedfor indicating the sending state, of the reference signal, adjusted bythe first communications node; and

adjusting, by the communications device, measurement of the referencesignal according to the adjusted sending state of the reference signal.

Preferably, the adjusting, by the communications device, measurement ofthe reference signal according to the adjusted sending state, of thereference signal, indicated by the indication information includes atleast one of the following:

determining, by the communications device according to the adjustedsending state, of the reference signal, indicated by the indicationinformation, whether to measure the reference signal;

measuring, by the communications device, the reference signal accordingto adjusted measurement configuration information indicated by theindication information;

no longer measuring, by the communications device, the reference signalaccording to an indication, of no longer measuring the reference signal,in the indication information; or

measuring, by the communications device, a first type of referencesignals according to an indication, of measuring the first type ofreference signals, in the indication information, where the first typeis different from a type of the adjusted reference signal.

Herein, corresponding to the signal transmission method in FIG. 15, thecommunications device may be UE, a base station or the like. Acommunications node of the cell in which the communications device islocated may be specifically a base station, a base station processor, UEor the like. When the communications node is UE herein, the foregoingmethod may be applied to a scenario of D2D communication, and a cell inwhich the UE is located refers to a signal coverage area formed byanother UE.

In a specific implementation process, a communications node of a cell inwhich a communications device is located adjusts a reference signal ofthe current cell to prevent another device from detecting or measuringor accessing the current cell, or to reduce a probability that theanother device detects or measures or accesses the current cell. At thesame time, to enable the communications device in the current cell toperform a normal measurement process, after receiving indicationinformation sent by the communications node of the current cell, thecommunications device performs related measurement adjustment accordingto the indication information. Specifically, the communications devicemay determine, according to an adjusted sending state, of the referencesignal, indicated by the indication information, whether to measure thereference signal whose sending state is adjusted; for example, when theadjusted sending state of the reference signal is stopping sending, thecommunications device determines to no longer measure the referencesignal of which sending is stopped. The communications device mayfurther measure, according to adjusted measurement configurationinformation indicated by the indication information, the referencesignal whose sending state is adjusted; for example, the measurementconfiguration information may be measurement configuration informationincluding an extended measurement period, and/or, may be measurementconfiguration information including a lowered bandwidth occupied formeasurement. The communications device may further no longer measure thereference signal according to the received indication information of nolonger measuring the reference signal. The communications device mayfurther measure, according to the received indication information ofmeasuring a set type of reference signals, the set type of referencesignals. Herein, to ensure a normal measurement process of thecommunications device in the current cell after the reference signal isadjusted, another type of reference signals, different from a type ofthe adjusted reference signal, may be set for the communications deviceto perform measurement.

Preferably, the receiving, by the communications device, indicationinformation sent by the first communications node includes at least oneof the following:

receiving, by the communications device by using a system informationblock SIB, the indication information sent by a communications node ofthe cell in which the communications device is located; receiving, byusing dedicated radio resource control RRC signaling, the indicationinformation sent by a communications node of the cell in which thecommunications device is located; receiving, by using a physical layerbroadcast message, the indication information sent by a communicationsnode of the cell in which the communications device is located; orreceiving, by using downlink control information DCI, the indicationinformation sent by a communications node of the cell in which thecommunications device is located.

In a specific implementation process, if the first communications nodedetermines to restore the sending state of the reference signal, thecommunications device may further receive the indication informationsent by the first communications node after the sending state of thereference signal is restored. A specific manner of receiving theindication information and a related operation performed according tothe indication information correspond to that the first communicationsnode sends the indication information, and are no longer elaboratedherein.

FIG. 18 is a flowchart of a signal transmission method according toEmbodiment 3 of the present invention, where the signal transmissionmethod includes:

S181: A communications device receives notification information sent bya first communications node, where the notification information is sentby the first communications node after the first communications nodeadjusts a sending state of a reference signal of a cell in which thecommunications device is located.

S182: The communications device receives, according to the notificationinformation, data and/or control signaling on a resource carrying thereference signal.

Herein, the communications device may be a wireless communicationsdevice such as UE or a base station, and a communications node of thecell in which the communications device is located may be UE, a basestation, a base station processor, or the like.

Preferably, the receiving, by the communications device, data and/orcontrol signaling on a resource carrying the reference signal includes:

receiving, by the communications device by using a physical layercontrol channel, the control signaling on the resource carrying thereference signal; and/or, receiving, by using a physical layer datachannel, the data on the resource carrying the reference signal.

Preferably, the receiving, by a communications device, notificationinformation sent by a first communications node includes at least one ofthe following:

receiving, by the communications device by using a system informationblock SIB, the notification information sent by the first communicationsnode; receiving, by using dedicated radio resource control RRCsignaling, the notification information sent by the first communicationsnode; receiving, by using a physical layer broadcast message, thenotification information sent by the first communications node; orreceiving, by using downlink control information DCI, the notificationinformation sent by the first communications node.

In a specific implementation process, if the first communications nodedetermines to restore the sending state of the reference signal, thecommunications device may further receive the notification informationsent after the first communications node restores the sending state ofthe reference signal. A specific manner of receiving the notificationinformation and a related operation performed according to thenotification information correspond to that the first communicationsnode sends the notification information, and are no longer elaboratedherein.

FIG. 19 is a flowchart of a signal transmission method according toEmbodiment 4 of the present invention, where the signal transmissionmethod includes:

S191: A first communications node receives an adjusted sending state, ofa reference signal of a neighboring cell, sent by a communications nodeof the neighboring cell.

S192: The first communications node controls, according to the receivedadjusted sending state of the reference signal of the neighboring cell,measurement of a cell of user equipment UE served by the firstcommunications node.

Preferably, in step S192, the controlling, by the first communicationsnode according to the received adjusted sending state of the referencesignal of the neighboring cell, measurement of a cell of user equipmentUE served by the first communications node includes:

determining, by the first communications node according to the receivedadjusted sending state of the reference signal of the neighboring cell,whether the UE served by the first communications node needs to measurethe neighboring cell, and/or, determining configuration information formeasuring the neighboring cell by the UE served by the firstcommunications node.

In a specific implementation process, after receiving the adjustedsending state, of the reference signal of the neighboring cell, sent bythe communications node of the neighboring cell, the firstcommunications node determines, according to the adjusted sending stateof the reference signal, whether UE in a current cell needs to measurethe neighboring cell. For example, if the adjusted sending state of thereference signal of the communications node of the neighboring cell isstopping sending the reference signal, the first communications nodedetermines that there is no need to measure a target cell. If theadjusted sending state of the reference signal of the firstcommunications node is lowering a sending power for sending and/orextending a sending period for sending and/or lowering an occupiedbandwidth for sending or the like, the communications node of theneighboring cell can determine that the UE still needs to measure thetarget cell, but measurement configuration information needs to beadjusted. If the first communications node extends the sending period tosend the reference signal, the communications node of the neighboringcell adjusts, according to the sending state of the reference signal, ameasurement period of the UE in the current cell, to enable the UE toshorten a period of measuring the target cell. For example, the firstcommunications node adjusts the sending state of the reference signal,and one time of sending in every 5 subframes is adjusted to one time ofsending in every 10 subframes. Therefore, the communications node of theneighboring cell adjusts the measurement period of measuring the targetcell by the UE in the current cell, so that measuring the target cell bythe UE in the current cell once in every 5 subframes is adjusted tomeasuring the target cell once in every 10 subframes. Correspondingly,if the first communications node lowers the occupied bandwidth to sendthe reference signal, the communications node of the neighboring celllowers a bandwidth occupied when the UE in the current cell measures thetarget cell. If the first communications node lowers the sending powerto send the reference signal, when determining that signal transmissionhas a path loss, the communications node of the neighboring cell uses anadjusted lowered sending power as a transmission power of the targetcell, and compares the adjusted lowered sending power with an actualreceived power, to determine the path loss, so as to determine ageographical relationship between the target cell and the neighboringcell.

FIG. 20 is a flowchart of a signal transmission method according toEmbodiment 5 of the present invention, where the signal transmissionmethod includes:

S201: A first communications node generates a reference signal, wherethe reference signal carries load information of a cell in which thefirst communications node is located.

S202: The first communications node sends the reference signal, wherethe reference signal is used for enabling a communications device thatdetects the reference signal to determine, according to the loadinformation, whether to measure the cell, or determine whether to reporta measurement result of measuring the cell, or determine whether toaccess the cell.

Preferably, in step S202, the sending, by the first communications node,the reference signal includes at least one of the following:

sending, by the first communications node, the reference signalaccording to a reference signal sending period corresponding to the loadinformation;

sending, by the first communications node, the reference signalincluding encoding information corresponding to the load information; or

sending, by the first communications node, the reference signal by usinga bandwidth corresponding to the load information.

FIG. 21 is a flowchart of a signal transmission method according toEmbodiment 6 of the present invention, where the signal transmissionmethod includes:

S211: A communications device receives a reference signal sent by afirst communications node, where the reference signal carries loadinformation of a cell in which the first communications node is located.

S212: The communications device determines, according to the loadinformation, whether to measure the cell, or determines whether toreport a measurement result of measuring the cell, or determines whetherto access the cell.

In a specific implementation process, the communications device maydetermine, according to a load condition indicated by the loadinformation, whether to measure the target cell, and report the targetcell to a communications node, for example, a base station, of a cell inwhich the managed communications device is located, or after the targetcell is measured, determine whether a measurement result needs to bereported to a communications node managing a current cell, or determinewhether to access the target cell. For example, the communicationsdevice and a network side agree on three types of load information,where the types include, in an ascending order of load, low load, highload, and over load. After determining, according to the loadinformation, that the target cell has over load, the communicationsdevice determines not to measure the target cell or determines not toaccess the target cell. Alternatively, after determining, according tothe load information, that the target cell has high load, thecommunications device determines to measure the target cell, and aftermeasurement, determines, in combination with the measurement result andthe load information, whether the measurement result needs to bereported to the communications node managing the communications device.

In a specific implementation process, the communications device mayreceive the reference signal, including load information of differenttarget cells, sent by different first communications nodes, andseparately determine whether to measure these target cells, or accordingto the received load information, based on a principle of preferentiallymeasuring a target cell having relatively low load, after an order ofmeasuring these target cells is arranged, sequentially report the targetcells to the communications node of the cell in which the managedcommunications device is located, to enable a target cell havingrelatively low load to be measured preferentially, thereby ensuring thata preferentially reported cell is a cell having a highest possibility toaccept the communications device.

Preferably, before the determining, by the communications deviceaccording to the load information, whether to measure the cell, ordetermining whether to report a measurement result of measuring thecell, or determining whether to access the cell, the method furtherincludes at least one of the following:

determining, by the communications device according to a referencesignal sending period of sending the reference signal by the firstcommunications node, the load information included in the referencesignal;

determining the load information according to encoding informationincluded in the reference signal; or

determining the load information according to a bandwidth occupied whenthe first communications node sends the reference signal.

According to an agreement with a network side or according to anindication by the first communications node, after receiving thereference signal, herein, the communications device may determine a loadcondition of the target cell according to the signal sending period ofsending the reference signal by the first communications node, and/or,determine a load condition of the target cell according to the encodinginformation included in the reference signal, and/or, determine a loadcondition of the target cell according to the bandwidth occupied whenthe first communications node sends the reference signal.

Preferably, the load information includes information about whether thetarget cell has over load as determined by the first communicationsnode. The determining, by the communications device according to theload information, whether to measure the target cell or determiningwhether to report a measurement result of measuring the target cell ordetermining whether to access the target cell includes:

if the load information is that the target cell has over load,determining not to measure the target cell or not to report themeasurement result or not to access the target cell.

In a specific implementation process, the load information may havevarious manifestation forms. For example, the load information may beclassified into two types, including over load and non-over load, or theload information may further be classified into low load, high load,over load, and the like.

By means of this embodiment of the present invention, a communicationsdevice does not need to read a system broadcast message of an RRC layerto acquire load information, and can acquire, without needing to readanother physical channel message, load information of a target cell atthe same time when the target cell is detected, and determine, accordingto the load information, whether to measure the target cell or determinewhether to report a measurement result of measuring the target cell ordetermine whether to access the target cell, thereby reducing someunnecessary processes of measurement and signaling interactions, andincreasing efficiency of cell handover.

To describe in detail the signal transmission method in this embodimentof the present invention, several relatively specific implementationmanners are listed below for introduction.

FIG. 22 is a flowchart of a signal transmission method according toImplementation Manner 1 of the present invention, where the signaltransmission method includes:

S221: A first communications node sends a reference signal, to enableanother device to detect or measure the first communications node.

Herein, the reference signal is sent by the first communications node,and may enable the another device to detect a signal of a target cellmanaged by the first communications node, where the reference signal mayinclude a cell identity, and may be specifically any one or more of asynchronization signal including a PSS and an SSS, a Discovery RS, aDetection RS, a CSI-RS, a CRS, and a DM-RS. Herein, the another devicemay be specifically UE, a base station, a base station processor, or thelike outside the target cell.

S222: The first communications node determines that a target cell isoverloaded.

Herein, that the target cell is overloaded refers to that a radioresource is overloaded, a backhaul link network is overloaded, ahardware resource is overloaded, or the like.

S223: The first communications node adjusts a sending state of thereference signal.

Herein, the adjusting a sending state of the reference signal may bespecifically: stopping sending the reference signal, to prevent theanother device outside the target cell from detecting or measuring oraccessing the target cell; or may further be: lowering a power to sendthe reference signal, to lower a coverage area of the reference signal,thereby reducing a quantity of devices that detect or measure or accessthe target cell; or may further be: extending a sending period to sendthe reference signal, so that a probability that the another devicedetects or measures or accesses the target cell is reduced; or mayfurther be: lowering an occupied bandwidth to send the reference signal,so that a coverage area of the reference signal can also be lowered.

FIG. 23 is a flowchart of a signal transmission method according toImplementation Manner 2 of the present invention, where the signaltransmission method includes:

S231: A first communications node determines that a sending state of areference signal needs to be adjusted, to prevent another device fromdetecting a target cell or measuring the target cell or accessing thetarget cell, or to reduce a probability that the another device fromdetecting the target cell or measuring the target cell or accessing thetarget cell.

S232: The first communications node adjusts the sending state of thereference signal.

Specifically, the adjusting the sending state of the reference signalmay be specifically: stopping sending the reference signal, to preventthe another device outside the target cell from detecting or measuringor accessing the target cell; or may further be: lowering a power tosend the reference signal, to lower a coverage area of the referencesignal, thereby reducing a quantity of devices that detect or measure oraccess the target cell; or may further be: extending a sending period tosend the reference signal, so that a probability that the another devicedetects or measures or accesses the target cell is reduced; or mayfurther be: lowering an occupied bandwidth to send the reference signal,so that a coverage area of the reference signal can also be lowered.

S232: The first communications node sends indication information to acommunications device in the target cell, where the indicationinformation is used for instructing the communications device in thetarget cell to determine, according to an adjusted sending state, of thereference signal, indicated by the indication information, whether tomeasure the reference signal whose sending state is adjusted; or,instructing the communications device in the target cell to measure,according to adjusted measurement configuration information indicated bythe indication information, the reference signal whose sending state isadjusted; or, instructing the communications device in the target cellto no longer measure the reference signal whose sending state isadjusted; or, instructing the communications device in the target cellto measure a set type of reference signals, where the set type isdifferent from a type of the reference signal whose sending state isadjusted.

In specific implementation, the first communications node may send theindication information to the communications device in the target cellin the following manners:

The first communications node broadcasts the indication information tothe communications device in the target cell by using an SIB; or, sendsthe indication information to the communications device in the targetcell by using dedicated RRC signaling; or, broadcasts the indicationinformation to the communications device in the target cell by using aphysical layer broadcast message; or, sends the indication informationto the communications device in the target cell by using DCI.

FIG. 24 is a flowchart of a signal transmission method according toImplementation Manner 3 of the present invention, where the signaltransmission method includes:

S241: A first communications node determines that a sending state of areference signal needs to be adjusted, to prevent another device fromdetecting a target cell or measuring the target cell or accessing thetarget cell, or to reduce a probability that the another device detectsthe target cell or measures the target cell or accesses the target cell.

S242: The first communications node adjusts the sending state of thereference signal.

S243: The first communications node notifies a communications device inthe target cell to receive data and/or control signaling on a resourcecarrying the reference signal.

Herein, the communications device may be UE, or may also be a devicesuch as a base station that has gained access to the target cell. Whenthe communications device is UE, herein, the first communications nodemay be a base station, or a base station processor, or may also beanother UE. When the first communications node is another UE, theimplementation manner is applicable to D2D communication.

FIG. 25 is a schematic diagram of notifying UE in a target cell of thatsending of a reference signal is stopped after a first communicationsnode has over load (over load), where the first communications node is apico base station (Pico eNB), and the reference signal is a Discovery RS(also referred to as a Detection RS), and is referred to as a D-RS forshort. After the first communications node stops sending referencesignals that need to be adjusted, resources occupied before sending ofthese reference signals is stopped are used to transmit data and/orcontrol signaling between the first communications node and all UEs orset UEs in the target cell. Herein, the first communications nodefurther notifies, by using an X2 interface, a communications node of aneighboring cell of information about over load of the target cell.

Preferably, in a specific implementation process, the firstcommunications node may notify, in a manner same as that of sending theindication information in Implementation Manner 2 above, acommunications device in the target cell to receive data and/or controlsignaling on a resource of the reference signal, including:

notifying, by the first communications node by using an SIB, thecommunications device in the target cell to receive data and/or controlsignaling on a resource carrying the reference signal; or,

notifying, by the first communications node by using dedicated RRCsignaling, the communications device in the target cell to receive dataand/or control signaling on a resource carrying the reference signal;or,

notifying, by the first communications node by using a physical layerbroadcast message, the communications device in the target cell toreceive data and/or control signaling on a resource carrying thereference signal; or

notifying, by the first communications node by using DCI, thecommunications device in the target cell to receive data and/or controlsignaling on a resource carrying the reference signal.

Preferably, the first communications node may send, by using a physicallayer control channel, control signaling to the communications device inthe target cell on a resource carrying the reference signal, or maysend, by using a physical layer data channel, data to the communicationsdevice in the target cell on a resource carrying the reference signal.

FIG. 26 is a flowchart of a signal transmission method according toImplementation Manner 4 of the present invention, where the signaltransmission method includes:

S261: A first communications node determines that a sending state of areference signal needs to be adjusted, to prevent another device fromdetecting a target cell or measuring the target cell or accessing thetarget cell, or to reduce a probability that the another device detectsthe target cell or measures the target cell or accesses the target cell.

S262: The first communications node adjusts the sending state of thereference signal.

S263: The first communications node notifies a communications node of aneighboring cell of an adjusted sending state of the reference signal ofthe target cell, to enable the communications node of the neighboringcell to determine, according to the adjusted sending state of thereference signal of the target cell, whether UE in the neighboring cellneeds to measure the target cell, or determine, after it is determinedthat the UE in the neighboring cell needs to measure the target cell,configuration information for measuring the target cell by the UE in theneighboring cell.

By means of this implementation manner, a communications node of aneighboring cell can perform corresponding measurement adjustmentaccording to a change of a sending state of a reference signal of afirst communications node, thereby reducing unnecessary processes ofmeasurement and signaling interactions of the communications node of theneighboring cell and UE of the neighboring cell.

FIG. 27 is a flowchart of a signal transmission method according toImplementation Manner 5 of the present invention, where the signaltransmission method includes:

S271: A first communications node sends a reference signal includingload information of a target cell.

S272: A communications device determines, according to the received loadinformation in the reference signal, whether to measure the target cell,or determines whether to report a measurement result of measuring thetarget cell, or determines whether to access the target cell.

In a specific implementation process, the first communications node maysend the reference signal including the load information of the targetcell in the following manners:

The first communications node may implicitly notify the communicationsdevice of the load information of the reference signal. That is, theload information is implicitly included in the reference signal; forexample, the reference signal is sent according to a reference signalsending period corresponding to the load information, or, the firstcommunications node occupies a bandwidth corresponding to the loadinformation to send the reference signal. The first communications nodemay also add the load information to the reference signal; for example,the first communications node sends the reference signal includingencoding information corresponding to the load information.

Correspondingly, the communications device determines the loadinformation according to the reference signal sending period, or,determines the load information according to the bandwidth occupied tosend the reference signal, or determines the load information accordingto the encoding information included in the reference signal, anddetermines, according to the determined load information, whether tomeasure the target cell, or determines whether to report the measurementresult of measuring the target cell, or determines whether to access thetarget cell.

By means of this implementation manner, a communications device does notneed to read a system broadcast message of an RRC layer to acquire loadinformation, and can acquire, without needing to read another physicalchannel message, load information of a target cell at the same time whenthe target cell is detected, and determine, according to the loadinformation, whether to measure the target cell, or determine, after itis determined to measure the target cell, in combination with ameasurement result, whether to report the measurement result, ordetermine whether to access the target cell, thereby reducing someunnecessary processes of measurement and signaling interactions, andincreasing efficiency of cell handover.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, division of theforegoing function modules is taken as an example for illustration. Inactual application, the foregoing functions can be allocated todifferent function modules and implemented according to a requirement,that is, an inner structure of a device is divided into differentfunction modules to implement all or some of the functions describedabove. For a detailed working process of the foregoing system, device,and unit, reference may be made to a corresponding process in theforegoing method embodiments, and details are not described hereinagain.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, device, and method maybe implemented in other manners. For example, the described apparatusembodiment is merely exemplary. For example, the module or unit divisionis merely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the shown or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the devices or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts shown as units may or may not be physical units, maybe located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentapplication may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

When the integrated unit is implemented in the form of a softwarefunctional unit and sold or used as an independent product, theintegrated unit may be stored in a computer-readable storage medium.Based on such understanding, the technical solutions of the presentapplication essentially, or the part contributing to the prior art, orall or some of the technical solutions may be implemented in the form ofa software product. The software product is stored in a storage mediumand includes several instructions for instructing a computer device(which may be a personal computer, a server, or a network device) or aprocessor (processor) to perform all or some of the steps of the methodsdescribed in the embodiments of the present application. The foregoingstorage medium includes: any medium that can store program code, such asa USB flash drive, a removable hard disk, a read-only memory (ROM,Read-Only Memory), a random access memory (RAM, Random Access Memory), amagnetic disk, or an optical disc.

The foregoing embodiments are merely used to describe the technicalsolutions of the present application. The foregoing embodiments aremerely intended to help understand the method and core idea of thepresent invention, and shall not be construed as a limitation on thepresent invention. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thepresent invention shall fall within the protection scope of the presentinvention.

What is claimed is:
 1. A communication device, comprising: a processor,configured to: adjust a sending state of a reference signal of a cellthat belongs to a first communications node in which the processor islocated, transmit an adjusted sending state of the reference signal, andextend a sending period of sending the reference signal of the cell; anda transmitter, configured to receive the adjusted sending state of thereference signal from the processor, and transmit the reference signalof the cell according to the adjusted sending state of the referencesignal.
 2. The device according to claim 1, wherein the processor isconfigured to: before adjusting the sending state of the referencesignal, determine that the sending state of the reference signal of thecell needs to be adjusted.
 3. The device according to claim 1, whereinthe transmitter is configured to: after the processor adjusts thesending state of the reference signal, send indication information toanother communication device in the cell for indicating to the othercommunications device in the cell to measure the reference signalaccording to adjusted measurement configuration information indicated bythe indication information.